Devin won a tiny bouncy ball at the school carnival. The diameter of the ball is 1.25 inches. To the nearest hundredth of a square inch, what is the surface area of the ball? Use 3.14 for pi.

A. 19.63 in^2
B. 4.91 in^2
C. 12.27 in62
D. 9.81 in^2

Question

Devin won a tiny bouncy ball at the school carnival. The diameter of the ball is 1.25 inches. To the nearest hundredth of a square inch, what is the surface area of the ball? Use 3.14 for pi.  

A. 19.63 in^2
B. 4.91 in^2
C. 12.27 in62
D. 9.81 in^2

anonymous · Answer

the surface area of a circle is 4*pi*r^2

anonymous · Answer

A?

anonymous · Answer

no, its not A, what numbers are you using?

anonymous · Answer

Oh, I see what you are doing wrong its simple, small mistake that's it

anonymous · Answer

so it was 4*3.14*d not r

anonymous · Answer

the equation is 4 times pi times r squared.  not d

anonymous · Answer

you have to find r first, which is simple, since they give you d, and r= d/2

anonymous · Answer

oh ok i get it it was 4.91 right?

anonymous · Answer

you got it

anonymous · Answer

thanks

anonymous · Answer

no problem :)