All Trigonometry Resources
Example Questions
Example Question #1 : Finding Angles
A plank has one end on the ground and one end off the ground. What is the measure of the angle formed by the plank and the ground?
The length of the plank becomes the hypotenuse of the triangle, while the distance between the plank and the ground becomes the length of one side. To solve for the angle between the plank and the ground, you must find the value of . The sine of the angle is the value of the opposite side over the hypotenuse, which are values that we know.
Example Question #1 : Finding Angles
Two angles in a triangle are and . What is the measure of the 3rd angle?
There is not enough information to determine the angle measure.
The sum of the angles of a triangle is 180˚.
Thus, since the sum of our two angles is 100˚, our missing angle must be,
.
Example Question #2 : Finding Angles
If the hypotenuse of a right triangle has a length of 6, and the length of a leg is 2, what is the angle between the hypotenuse and the leg?
The leg must be an adjacent side to the hypotenuse.
Therefore, we can use inverse cosine to solve for the angle.
First write the equation for sine of an angle.
Substitute the lengths given and solve for the angle.
Example Question #3 : Finding Angles
A skateboard ramp made so that the rider can gain sufficient speed before a jump is 15 feet high and the ramp is 17 feet long. What is the measure of the angle between the ramp and the ground?
None of the other answers.
For the angle in question we have the opposite side and the hypotenuse given to us. We can use the sine function.
Use the inverse sin to find the measure of an angle between these sides:
Example Question #2 : Finding Angles
What angle does the ramp make with the bottom of the stair?
Example Question #1 : Solving Triangles
Given that angle A is 23.0o, side a is 1.43 in., and side b is 3.62 in., what is the angle of B?
70o
81.5o
83.6o
55o
90o
81.5o
Example Question #367 : Trigonometry
Artemis wants to build a ramp to make the entrance to their home more accessible. The angle between the ramp and the ground cannot be more than steep. Artemis has feet of space in their yard that the ramp can take up, and the distance between the ground and the house entrance is feet high. Will Artemis be able to build a ramp that complies with the standard?
Yes
No
No
Begin the problem by visualizing a diagram of the situation:
We can use inverse trig to solve for the unknown angle .
Because this angle is larger than , this ramp would not comply with standards.
Example Question #368 : Trigonometry
If the hypotenuse of a right triangle has a length of 42.29 meters, and the length of a leg is 12.88 meters, what is the angle between the hypotenuse and the leg?
The leg must be an adjacent side to the hypotenuse.
Therefore, we can use inverse cosine to solve for the angle.
First write the equation for sine of an angle.
Substitute the lengths given and solve for the angle.
Example Question #1 : Finding Sides
If the height of the stair is 2 ft, and the length of the stair is 3 ft, how long must the ramp be to cover the stair?
5 ft
10 ft
2.5 ft
13 ft
3.6 ft
3.6 ft
Use the Pythagorean triangle to solve for the third side of the triangle.
Simplify and you have the answer:
Example Question #2 : Finding Sides
A surveyor looks up to the top of a mountain at an angle of 35 degrees. If the surveyor is 2400 feet from the base of the mountain, how tall is the mountain (to the nearest tenth of a foot)?
3427.6 feet
1966.0 feet
1376.6 feet
2135.8 feet
1680.5 feet
1680.5 feet
This is a typical angle of elevation problem.
From the question, we can infer that the ratio of the mountain height to the surveyor's horizontal distance from the mountain is equal to the tangent of 35 degrees - the mountain height is the "opposite side", while the horizontal distance is the "adjacent side". In other words:
Solving for the mountain height gives a vertical distance of 1680.5 feet.
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