JAMB - Mathematics (2002 - No. 28)
The sum of the interior angles of a polygon is 20 right angles. How many sides does the polygon have?
12
20
40
10
Penjelasan
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.