Question

MEDAL!!!!
A spherical balloon has a circumference of 19cm. What is the approximate surface area of the balloon to the nearest square centimeter?
A. 115cm^2
B. 460cm^2
C.361cm^2
D.1,134cm^2

Answer 1

find radius frm circumference

Answer 2

so first, what is the formula for surface area?

Answer 3

what is the formula again?

Answer 4

well I am asking you, jessie

Answer 5

\[4*\pi *r*r=surface area of sphere \]

Answer 6

ok, so jessie, now what is the formula for circumference

Answer 7

4*pi*r*r

Answer 8

that is not circumference 4pi r squared is the formula for surface area

Answer 9

so whats the formula i forgot

Answer 10

circumference = 2*pi*R

Answer 11

2*pi*9.5 right

Answer 12

59.66

Answer 13

you don't know r yet, so you cannot put it in. You need to solve \[C=2\pi r\] for r. Please do this

Answer 14

ok..
19=2pi r

Answer 15

A)

Answer 16

how did u get A

Answer 17

so solve that for r now please