Question

George makes large cookies. These cookies are 18 inches in diameter. How much icing will he need to cover the top of each cookie?

18π in2

324π in2

81π in2

9π in2

Answer 1

@Jamierox4ev3r

Answer 2

you need to find the area
A = pi.r^2

Answer 3

what r and what does r^2 mean

Answer 4

r is the radius

r^2 means "r squared"

Answer 5

oh yea my Bad

Answer 6

that's ok, glad you asked

Answer 7

do you know what is r equal to ?

Answer 8

would it be 324

Answer 9

r is NOT 18

Answer 10

18 is the diameter (not the radius)

Answer 11

ok

Answer 12

9

Answer 13

diameter = 18, and r (radius) equal half of 18

Answer 14

good, r = 9

now square both sides

Answer 15

81

Answer 16

good

Answer 17

right

Answer 18

81π in2

Answer 19

thanks'

Answer 20

@Hero

Answer 21

All you need to do is use the formula \(A = \pi r^2\) You have to convert radius to diameter. \(r = \frac{d}{2}\) so

\[A = \pi \left(\frac{d}{2}\right)^2\]

d = 18

Input d into the formula and simplify

Answer 22

18/2=9
9^2=81

Answer 23

Don't ignore pi

Answer 24

81pi