geometry
posted by sita .
find the area of the sector with 80 degree angle and radius=8

Area = 1/2 r² θ
Sound familiar? The whole circle has 2π radians, so the area = 1/2 * 2π r^2 = πr^2
Anyway, you have 80°, which is 80*/360 * 2π = 2π/9
So, the area is 1/2 * 2π/9 * 8² = 22.34