The sum of the interior angles of a polygon is 20 right angles. How many sides does the polygon have?
-
A.
12 -
B.
20 -
C.
40 -
D.
10
Correct Answer: Option A
Explanation
The formula for the sum of the interior angles of a regular polygon = (2n – 4) x 90°
Given: Sum = 20 right angles
(2n – 4) x 90° = 20 times 90°
⇒ 2n – 4 = 20
2n = 24; n = 12.