WAEC - Mathematics (2005 - No. 33)
A regular polygon has 9 sides. What is the size of one of its exterior angles?
20o
40o
90o
140o
คำอธิบาย
Exterior angle \(=\frac{360}{n}\) where n = no of sides
\(=\frac{360}{9}=40^{\circ}\)
\(=\frac{360}{9}=40^{\circ}\)