Geometry - ACT Math
Card 0 of 7119
In a right triangle a hypotenuse has a length of 8 and leg has a length of 7. What is the length of the third side to the nearest tenth?
In a right triangle a hypotenuse has a length of 8 and leg has a length of 7. What is the length of the third side to the nearest tenth?
Using the pythagorean theorem, 82=72+x2. Solving for x yields the square root of 15, which is 3.9
Using the pythagorean theorem, 82=72+x2. Solving for x yields the square root of 15, which is 3.9
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What is the hypotenuse of a right triangle with sides 5 and 8?
What is the hypotenuse of a right triangle with sides 5 and 8?
Because this is a right triangle, we can use the Pythagorean Theorem which says _a_2 + _b_2 = _c_2, or the squares of the two sides of a right triangle must equal the square of the hypotenuse. Here we have a = 5 and b = 8.
_a_2 + _b_2 = _c_2
52 + 82 = _c_2
25 + 64 = _c_2
89 = _c_2
c = √89
Because this is a right triangle, we can use the Pythagorean Theorem which says _a_2 + _b_2 = _c_2, or the squares of the two sides of a right triangle must equal the square of the hypotenuse. Here we have a = 5 and b = 8.
_a_2 + _b_2 = _c_2
52 + 82 = _c_2
25 + 64 = _c_2
89 = _c_2
c = √89
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A right triangle has side lengths of 21 and 72. What is the length of the hypotenuse?
A right triangle has side lengths of 21 and 72. What is the length of the hypotenuse?
By the Pythagorean Theorem, 212 + 722 = hyp2. Then hyp2 = 5625, and the hypotenuse = 75. If you didn't know how to figure out that 752 = 5625, that's okay. Look at the answer choices. We could easily have squared them and chosen the answer choice that, when squared, equals 5625.
By the Pythagorean Theorem, 212 + 722 = hyp2. Then hyp2 = 5625, and the hypotenuse = 75. If you didn't know how to figure out that 752 = 5625, that's okay. Look at the answer choices. We could easily have squared them and chosen the answer choice that, when squared, equals 5625.
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Given a right triangle with a leg length of 2 and a hypotenuse length of √8, find the length of the other leg, x.

Given a right triangle with a leg length of 2 and a hypotenuse length of √8, find the length of the other leg, x.
Using Pythagorean Theorem, we can solve for the length of leg x:
_x_2 + 22 = (√8)2 = 8
Now we solve for x:
_x_2 + 4 = 8
_x_2 = 8 – 4
_x_2 = 4
x = 2
Using Pythagorean Theorem, we can solve for the length of leg x:
_x_2 + 22 = (√8)2 = 8
Now we solve for x:
_x_2 + 4 = 8
_x_2 = 8 – 4
_x_2 = 4
x = 2
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A deer walks in a straight line for 8 hours. At the end of its journey, the deer is 30 miles north and 40 miles east of where it began. What was the average speed of the deer?
A deer walks in a straight line for 8 hours. At the end of its journey, the deer is 30 miles north and 40 miles east of where it began. What was the average speed of the deer?
To find the speed of the deer, you must have the distance traveled and the time.
The distance is found using the Pythagorean Theorem:




The answer must be in miles per hour so the total miles are divided by the hours to get the final answer:

To find the speed of the deer, you must have the distance traveled and the time.
The distance is found using the Pythagorean Theorem:
The answer must be in miles per hour so the total miles are divided by the hours to get the final answer:
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What is the slope of the line given by the equation
?
What is the slope of the line given by the equation ?
To find the slope, put the line in slope intercept form. In other words put the equation in
form where
represents the slope and
represents the y-intercept.



From here we can see our slope equals
:

To find the slope, put the line in slope intercept form. In other words put the equation in form where
represents the slope and
represents the y-intercept.
From here we can see our slope equals :
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Find the distance between
and 
Find the distance between and
The expression used in solving this question is the distance formula: 
This formula is simply a variation of the Pythagorian Theorem. A great way to remember this formula is to visualize a right triangle where two of the vertices are the points given in the problem statement. For this question: 
Where a =
and b =
. Now it should be easy to see how the distance formula is simply a variation of the Pythagorean Theorem.
We almost have all of the information we need to solve the problem, but we still need to find the coordinates of the triangle at the right angle. This can be done by simply taking the y-coordinate of the first point and the x-coordinate of the second point, resulting in
.
Now we can simply plug and chug using the distance formula. 

The expression used in solving this question is the distance formula:
This formula is simply a variation of the Pythagorian Theorem. A great way to remember this formula is to visualize a right triangle where two of the vertices are the points given in the problem statement. For this question:
Where a = and b =
. Now it should be easy to see how the distance formula is simply a variation of the Pythagorean Theorem.
We almost have all of the information we need to solve the problem, but we still need to find the coordinates of the triangle at the right angle. This can be done by simply taking the y-coordinate of the first point and the x-coordinate of the second point, resulting in .
Now we can simply plug and chug using the distance formula.
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Which point satisfies the system
and 
Which point satisfies the system and
In order to solve this problem, we need to find a point that will satisfy both equations. In order to do this, we need to combine the two equations into a single expression. For this, we need to isolate either x or y in one of the equations. Since the equation
already has y isolated, we will use this equation. Next we substitue this equation into the first one.
becomes
which simplifies to
. Now we can solve for x by factoring:
Thus,
.
Now that we have two possible values for x, we can plug each value into either equation to obtain two values for y. For
and the second equation, we get
. Therefore our first point is
. This is not one of the listed answers, so we will use our other value of x. For
and the second equation, we get
. This gives us the point
, which is one of the possible answers.
In order to solve this problem, we need to find a point that will satisfy both equations. In order to do this, we need to combine the two equations into a single expression. For this, we need to isolate either x or y in one of the equations. Since the equation already has y isolated, we will use this equation. Next we substitue this equation into the first one.
becomes
which simplifies to
. Now we can solve for x by factoring:
Thus,
.
Now that we have two possible values for x, we can plug each value into either equation to obtain two values for y. For and the second equation, we get
. Therefore our first point is
. This is not one of the listed answers, so we will use our other value of x. For
and the second equation, we get
. This gives us the point
, which is one of the possible answers.
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Find the distance between the points
and
.
Find the distance between the points and
.
The easiest way to find the distance between two points whose coordinates are given in the form
and
is to use the distance formula.

Plugging in the coordinates from our given points, our formula looks as follows

We then simply simplify step by step

Therefore, the distance between the two points is 13.
The easiest way to find the distance between two points whose coordinates are given in the form and
is to use the distance formula.
Plugging in the coordinates from our given points, our formula looks as follows
We then simply simplify step by step
Therefore, the distance between the two points is 13.
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What is the midpoint between the points
and
?
What is the midpoint between the points and
?
To find the midpoint, find the midpoint (or just average) for the x and y value separately. For the x-value, this means:
. For the y-value, this means:
. Thus, the midpoint is (3,4).
To find the midpoint, find the midpoint (or just average) for the x and y value separately. For the x-value, this means: . For the y-value, this means:
. Thus, the midpoint is (3,4).
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Find the distance between the two points
and
.
Find the distance between the two points and
.
Instead of memorizing the distance formula, think of it as a way to use the Pythagorean Theorem. In this case, if you draw both points on a coordinate system, you can draw a right triangle using the two points as corners. The result is a 5-12-13 triangle. Thus, the missing side's length is 13 units. If you don't remember this triplet, then you could use the Pythagorean Theorem to solve.
Instead of memorizing the distance formula, think of it as a way to use the Pythagorean Theorem. In this case, if you draw both points on a coordinate system, you can draw a right triangle using the two points as corners. The result is a 5-12-13 triangle. Thus, the missing side's length is 13 units. If you don't remember this triplet, then you could use the Pythagorean Theorem to solve.
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What is the measurement of
?
What is the measurement of ?
Whenever you have an angle that is inscribed to the outside edge of a circle and to an angle that passes through the midpoint of the circle, the inscribed angle will always be one half the measurement of the angle that passes through the midpoint of the circle.
Since the angle that passes through the midpoint of the circle is a straight angle (all straight angles measure
degrees), the inscribed angle must measure
degrees.

Since the sum of the internal angles of all triangles add up to
degrees, add up the measurements of the angles that you know and subtract the sum from
degrees to find your answer:


Whenever you have an angle that is inscribed to the outside edge of a circle and to an angle that passes through the midpoint of the circle, the inscribed angle will always be one half the measurement of the angle that passes through the midpoint of the circle.
Since the angle that passes through the midpoint of the circle is a straight angle (all straight angles measure degrees), the inscribed angle must measure
degrees.
Since the sum of the internal angles of all triangles add up to degrees, add up the measurements of the angles that you know and subtract the sum from
degrees to find your answer:
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What is the measurement of
?
What is the measurement of ?
If you extend the lines of the parellelogram, you will notice that a parellogram is the same as 2 different sets of parellel lines intersecting one another. When that happens, the following angles are congruent to one another:

Therefore, 
If you extend the lines of the parellelogram, you will notice that a parellogram is the same as 2 different sets of parellel lines intersecting one another. When that happens, the following angles are congruent to one another:
Therefore,
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AB and CD are two parrellel lines intersected by line EF. If the measure of angle 1 is
, what is the measure of angle 2?
AB and CD are two parrellel lines intersected by line EF. If the measure of angle 1 is , what is the measure of angle 2?
The angles are equal. When two parallel lines are intersected by a transversal, the corresponding angles have the same measure.
The angles are equal. When two parallel lines are intersected by a transversal, the corresponding angles have the same measure.
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In a poll, Camille learned that
of her classmates spoke English at home,
spoke Spanish, and
spoke other languages. If she were to graph this data on a pie chart, what would be the degree measurement for the part representing students who speak Spanish at home?
In a poll, Camille learned that of her classmates spoke English at home,
spoke Spanish, and
spoke other languages. If she were to graph this data on a pie chart, what would be the degree measurement for the part representing students who speak Spanish at home?
In order to solve this problem, you must first solve for what percentage of the entire group comprise of Spanish-speaking students. To do this, divide the total amount of Spanish-speaking students by the total number of students.

Multiply this number by 100 and round up in order to get your percentage.

Then, multiply this number times the total degrees in a circle to find out the measurement of the piece representing Spanish-speaking students on the pie chart.


Round up:

In order to solve this problem, you must first solve for what percentage of the entire group comprise of Spanish-speaking students. To do this, divide the total amount of Spanish-speaking students by the total number of students.
Multiply this number by 100 and round up in order to get your percentage.
Then, multiply this number times the total degrees in a circle to find out the measurement of the piece representing Spanish-speaking students on the pie chart.
Round up:
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Which of the following is the slope-intercept form of
?
Which of the following is the slope-intercept form of ?
To answer this question, we must put the equation into slope-intercept form, meaning we must solve for
. Slope-intercept form follows the format
where
is the slope and
is the intercept.
Therefore, we must solve the equation so that
is by itself. First we add
to both sides so that we can start to get
by itself:

Then, we must subtract
from both sides:

We then must divide each side by 

Therefore, the slope-intercept form of the original equation is
.
To answer this question, we must put the equation into slope-intercept form, meaning we must solve for . Slope-intercept form follows the format
where
is the slope and
is the intercept.
Therefore, we must solve the equation so that is by itself. First we add
to both sides so that we can start to get
by itself:
Then, we must subtract from both sides:
We then must divide each side by
Therefore, the slope-intercept form of the original equation is .
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Following the line
, what is the distance from the the point where
to the point where
?
Following the line , what is the distance from the the point where
to the point where
?
The first step is to find the y-coordinates for the two points we are using. To do this we plug our x-values into the equation. Where
, we get
, giving us the point
. Where
, we get
, giving us the point
.
We can now use the distance formula:
.
Plugging in our points gives us 
The first step is to find the y-coordinates for the two points we are using. To do this we plug our x-values into the equation. Where , we get
, giving us the point
. Where
, we get
, giving us the point
.
We can now use the distance formula: .
Plugging in our points gives us
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The coordinates of the endpoints of
, in the standard
coordinate plane, are
and
. What is the
-coordinate of the midpoint of
?
The coordinates of the endpoints of , in the standard
coordinate plane, are
and
. What is the
-coordinate of the midpoint of
?
To answer this question, we need to find the midpoint of
.
To find how far the midpoint of a line is from each end, we use the following equation:

and
are taken from the
value of the second point and
and
are taken from the
value of the first point. Therefore, for this data:

We can then solve:

Therefore, our midpoint is
units between each endpoint's
value and
unit between each endpoint's
value. To find out the location of the midpoint, we subtract the midpoint distance from the
point. (In this case it's the point
.) Therefore:


So the midpoint is located at 
The question asked us what the
-coordinate of this point was. Therefore, our answer is
.
To answer this question, we need to find the midpoint of .
To find how far the midpoint of a line is from each end, we use the following equation:
and
are taken from the
value of the second point and
and
are taken from the
value of the first point. Therefore, for this data:
We can then solve:
Therefore, our midpoint is units between each endpoint's
value and
unit between each endpoint's
value. To find out the location of the midpoint, we subtract the midpoint distance from the
point. (In this case it's the point
.) Therefore:
So the midpoint is located at
The question asked us what the -coordinate of this point was. Therefore, our answer is
.
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If
,
, and
, what is the measure, in degrees, of
?

If ,
, and
, what is the measure, in degrees, of
?
The question states that
. The alternate interior angle theorem states that if two parallel lines are cut by a transversal, then pairs of alternate interior angles are congruent; therefore, we know the following measure:

The sum of angles of a triangle is equal to 180 degrees. The question states that
; therefore we know the following measure:

Use this information to solve for the missing angle: 


The degree measure of a straight line is 180 degrees; therefore, we can write the following equation:


The measure of
is 148 degrees.
The question states that . The alternate interior angle theorem states that if two parallel lines are cut by a transversal, then pairs of alternate interior angles are congruent; therefore, we know the following measure:
The sum of angles of a triangle is equal to 180 degrees. The question states that ; therefore we know the following measure:
Use this information to solve for the missing angle:
The degree measure of a straight line is 180 degrees; therefore, we can write the following equation:
The measure of is 148 degrees.
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In the following diagram, lines
and
are parallel to each other. What is the value for
?

In the following diagram, lines and
are parallel to each other. What is the value for
?
When two parallel lines are intersected by another line, the sum of the measures of the interior angles on the same side of the line is 180°. Therefore, the sum of the angle that is labeled as 100° and angle y is 180°. As a result, angle y is 80°.
Another property of two parallel lines that are intersected by a third line is that the corresponding angles are congruent. So, the measurement of angle x is equal to the measurement of angle y, which is 80°.
When two parallel lines are intersected by another line, the sum of the measures of the interior angles on the same side of the line is 180°. Therefore, the sum of the angle that is labeled as 100° and angle y is 180°. As a result, angle y is 80°.
Another property of two parallel lines that are intersected by a third line is that the corresponding angles are congruent. So, the measurement of angle x is equal to the measurement of angle y, which is 80°.
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