If a tennis ball has a diameter of approximately 6.5 centimeters, what is its surface area?

Question

raden · Answer

use the formula :
surface area = 4 pi r^2
with r is radius

anonymous · Answer

whats the answer?

raden · Answer

what is 4 * 3.14 * 6.5^2 = ... ?

anonymous · Answer

530.66

anonymous · Answer

not an option

anonymous · Answer

628.57 square feet

427.43 square feet

1,335.71 square feet

854.86 square feet

raden · Answer

that's right
u have to convert units cm^2 to square ft :)

anonymous · Answer

how!?

raden · Answer

that's the problem.. i dont know too 
try googling it :)

anonymous · Answer

help!

raden · Answer

http://www.metric-conversions.org/length/centimeters-to-feet.htm

anonymous · Answer

aha
ok radius is half the diameter --> 1/2*6.5 = 3.25

SA = 4*pi*(3.25)^2
pi is 3.14
SA = 4(3.14)(3.25)^2 = 132.7

For surface area and volume you need to use and be familar with the formulas, thats all i was saying

anonymous · Answer

thanks can u help me some more? @nader1

anonymous · Answer

http://openstudy.com/study#/updates/5158f430e4b0507ceba2393a @nader1