Question

C) The ratio between an exterior angle and an interior angle of a polygon is 1:5.

i) Find the magnitude of an exterior angle.
ii) How many sides are there in this polygon?

Answer 1

30° and 12

Explanation:

The sum of the exterior angle and the interior angle = 180°

sum the parts of the ratio, 1 + 5 = 6 parts

Divide 180° by 6 to find the value of one part of the ratio

180° ÷ 6 = 30° ← value of 1 part of the ratio

(i)

The exterior angle = 30°

(ii)

The sum of the exterior angles of a polygon is 360°

To find the number of sides n divide 360 by 30 , that is

n = 360 ÷ 30 = 12