Question

Use the given circumference to find the surface area of each spherical object. Round your answer to the nearest whole number.
13. a grapefruit with C = 14 cm

Answer 1

well if the circumference is 14 cm

use

\[C = 2\pi r\]

to find the radius

so

\[14 = 2\pi r\]

just make r the subject.

then substitute your value of r into the surface area of a sphere formula
shown below

\[SA = 4\pi r^2\]

hope this helps

Answer 2

to get r do i do 14/2 pi

Answer 3

thats right so its now

\[SA = 4 \pi \times (\frac{14}{2\pi})^2\]

now just do the arithmetic

Answer 4

i must be doing something wrong because i got 1934 pi

Answer 5

probably the way you have entered it

I've squared 14/2pi

look at the common factors that cancel



now calculate