Engineering Board Exam Reviewer · Polygons · medium

Find the number of diagonals in a regular polygon with 15 sides.

1. 90
2. 105
3. 75
4. 120

Answer

A. 90

Solution

Diagonals = 152-15=105-15=90.

More Polygons questions

1. The sum of the interior angles of a polygon is 1980°. How many sides does it have?
2. Find the area of a regular hexagon with side length 8 cm.
3. A regular polygon has an interior angle of 165°. Find the number of sides.
4. A regular hexagon is inscribed in a circle of radius 8. Find the area inside the circle but outside the hexagon.
5. A regular octagon has a side of 6. Find the radius of its circumscribed circle.
6. Find the area of a regular dodecagon inscribed in a circle of radius 10.
7. A regular decagon is inscribed in a circle of radius 10. Find the length of one side.
8. Find the area of a regular octagon whose side is 4.
9. Find the apothem of a regular pentagon whose side is 10.
10. Find the area of a regular hexagon whose side is 6.

All Polygons questions