Sphere: The surface area of a sphere is found by multiplying four times π times the radius times the radius. SA = 4πr2 SA = 4 × × × r r which means π Example: SA = 4πr2 = 4 × × 5 × 5 π = 314.16 m2 5m Pyramid: The surface area of a pyramid is found by multiplying 2 times the base edge of the pyramid (b) times the slant height (s) plus the base edge of the pyramid (b) times the base edge of the pyramid (b). SA = 2bs + b2 SA = 2 × b × s + b × b which means Example: SA = 2bs + b2 = 2 × 12 × 9 + 12 × 12 9 m = 216 + 144 = 260 m2 12 m 12 m
Sphere: The surface area of a sphere is found by multiplying four times π times the radius times the radius. SA = 4πr2 which means SA = 4 × π × r × r Example: SA = 4πr2 = 4 × π × 5 × 5 = 314.16 m2 5m Pyramid: The surface area of a pyramid is found by multiplying 2 times the base edge of the pyramid (b) times the slant height (s) plus the base edge of the pyramid (b) times the base edge of the pyramid (b). SA = 2bs + b2 which means SA = 2 × b × s + b × b Example: SA = 2bs + b2 = 2 × 12 × 9 + 12 × 12 9 m = 216 + 144 = 260 m2 12 m 12 m