SAT Math : How to find the length of a side of a polygon
Study concepts, example questions & explanations for SAT Math
All SAT Math Resources
Example Questions
Example Question #1 : Other Polygons
If the following shape was going to be drawn in a circle, what is the minimum radius of the circle?
9
7
10
11
8
7
IF you draw the longest diagonal across the shape, the length of it is 13.4. This means the radius must be at least 6.7. The answer is 7.
Example Question #1 : Other Polygons
Each side of the above octagonal track is 264 feet in length. Julie starts at point A and runs clockwise at a steady speed of nine miles an hour for nine minutes. When she is finished, which of the following points is closest to her?
Point G
Point F
Point C
Point D
Point E
Point D
Julie runs for nine minutes, or hour; she runs nine miles per hour. Setting and in the rate formula, we can evaluate distance in miles:
Julie runs miles, which converts to feet by multiplication by 5,280 feet per mile:
feet.
Each side of the octagonal track measures 264 feet, so Julie runs
sides of the track; this is equivalent to running the entire track three times, then three more sides. She is running clockwise, so three more sides from Point A puts her at Point D. This is the correct response.
Example Question #2 : Other Polygons
Plato High School has an unusual track in that it is shaped like a regular octagon. The track has a perimeter of two-fifths of a mile.
Boris starts at Point A and runs clockwise until he gets halfway between Point E and Point F. Which of the following responses comes closest to the number of feet he runs?
1,500 feet
1,300 feet
1,200 feet
1,400 feet
1,100 feet
1,200 feet
One mile comprises 5,280 feet; the perimeter of the track, two-fifths of a mile, is equal to
feet.
Each (congruent) side of the octagonal track measures one-eighth of this,
feet.
By running clockwise from Point A to halfway between Point E and Point F, Boris runs along four and one half sides, each of which has this length, for a total running distance of
feet.
Of the five responses, 1,200 comes closest.
All SAT Math Resources
