Question

how do you find the surface area of a sphere with a Radius of 15cm using this formula SA = 4πr 2

Answer 1

replace r with 15

Answer 2

\(SA = 4 \pi \color{red}r^2\)

\(\color{red}{r = 15~cm} \)

Answer 3

plug that ^^^ into your calculator....

Answer 4

but i need to show work

Answer 5

\(SA=4\pi r^2 \implies SA = 4\pi15^2= 4*\pi*150=150*4*\pi=900\pi cm^2\)

Answer 6

you see?

Answer 7

yes

Answer 8

15^2 = 225

Answer 9

\(SA = 4 \pi \color{red}r^2\)

\(SA = 4 \pi \color{red}{(15~cm)}^2\)

\(SA = 4 \pi \times 225~cm^2\)

\(SA = 900\pi ~cm^2\)