Respuesta :
1. Find the surface area of a sphere with a circumference of 86 cm. Round to the nearest tenth.
C = 2πr
r = C / 2π = 86/2π = 43/π cm
A = 4πr^2 = 4π(43/π)^2 = 2,354.2 cm2
A. 2,354.2 cm2
2. A balloon has a circumference of 16 cm. Use the circumference to approximate the surface area of the balloon to the nearest square centimeter.
C = 2πr
r = C / 2π = 16/2π = 8/π cm
A = 4πr^2 = 4π(8/π)^2 = 81 cm^2
D. 81 cm2
C = 2πr
r = C / 2π = 86/2π = 43/π cm
A = 4πr^2 = 4π(43/π)^2 = 2,354.2 cm2
A. 2,354.2 cm2
2. A balloon has a circumference of 16 cm. Use the circumference to approximate the surface area of the balloon to the nearest square centimeter.
C = 2πr
r = C / 2π = 16/2π = 8/π cm
A = 4πr^2 = 4π(8/π)^2 = 81 cm^2
D. 81 cm2