Question

Use the given circumference to find the surface area of the spherical object.
A pincushion with C = 12 cm
The surface area of the pincushion is _____ cm^2
(Round to the nearest whole number as needed)

Answer 1

Surface area of a sphere is given A=4πr2
So...you have to find the radius from the given circumference

gimme a sec

Answer 2

Please use Circumference to calculate the Radius.

Circumference / ??? = Diameter
Diameter / ?? = Radius

Answer 3

A=4πr2
C = 12 cm = diameter x pi (divide 12 by pi)
C = 3.8 (about) x pi (divide 3.8 by 2 to get radius, since d=2r)
r - 1.9
A = 4 x pi x 1.9^2 (plug it all in and calculate)
A = 45.36
45

Answer 4

So 45 would be the surface area of the pincushion

Answer 5

Well, except for the rounding issues. The actual answer is 46. Too much intermediate rounding.

C = 12
D = C/pi = 12/pi
r = D/2 = D/2 = (12/pi)/2 = 6/pi
SA = 4*pi*r^2 = 4*pi*(6/pi)^2 = 4*6^2 * pi/(pi^2) = 4*36/pi = 144/pi = 45.8366 ==> 46 with no intermediate rounding.

Answer 6

Whoops. I left off all the units. Sorry about that. Don't feel like rewriting it.

Answer 7

alright well i appricate it yall, thank you.