JAMB - Mathematics (2009 - No. 23)
A regular polygon has 150º as the size of each interior angle. How many sides does it have?
12
10
9
8
คำอธิบาย
Sum of interior angles of a polygon = each interior ∠ x n
(n-2)180 = 150 x n
180n - 360 = 150n
180n-150n = 360
30n = 360
n = 360/30
n = 12 sides
(n-2)180 = 150 x n
180n - 360 = 150n
180n-150n = 360
30n = 360
n = 360/30
n = 12 sides