WAEC - Mathematics (1991 - No. 45)
In a given regular polygon, the ratio of the exterior angle to the interior angles is 1:3. How many side has the polygon?
40
5
6
8
12
Explication
Let x be the exterior angle; interior = 3x; but x + 3x = 180o
4x = 180o; x = 45
= \(\frac{360}{45}\) = 8
4x = 180o; x = 45
= \(\frac{360}{45}\) = 8