If the are of the cirlce is 121 pi centimeters, what is the diameter of the circle?

Question

formula for area of cirlce is pi times the radius squared

Answer 1

So r is the square root of 121, in other words, r=11. Now, the circumferenceis 2*pi*r=22pi centimeters.

By the way, the area would be 121pi *square* centimeters since a centimeter is a measure of length, not area.

Answer 2

The formula fot the area of a circle is A= PI*r^2
Substitute 121*Pi for the area in the equation.
121*PI = PI*r^2 divide by PI on both sides
121 = r^2 take the square root of both sides
r = 11

Answer 3

i assume you mean 121 pi centimeters-squared, since it is an area

the diameter is equal to twice the radius, and you already have the formula with the radius

so, pi*r^2=121*pi

divide both sides by pi and get:

r^2 =121

take the square root of both sides (neglect the negative root, this is a dimension and can't be negative) and get

r=11

or diameter = 2*r=22

good luck

Answer 4

the diameter is 22 centimeters..

solution: area of circle = pi * radius ^ 2
here, pi * radius ^ 2 = pi * 121
thus, radius ^ 2 = 121
thus, radius = 11
diameter is radius * 2
thus, diameter is 11 * 2 = 22 centimeters

Answer 5

Gee, thanks for the formula.

A = 121*pi = pi*r^2
r^2 = 121
r = 11

Since the radius is 11, the diameter is 22 cm

formula for diameter of circle is 2 times the radius

Answer 6

A = pi*r^2
diameter = 2r

Area = 121*pi cm^2 = pi*r^2

121 cm^2 = r^2
r = 11cm


diameter = 2*11 cm = 22cm

Answer 7

squar root of 121 is 11
11 = R
2R = D
11 * 2 = 22.

Answer 8

Area = Pi * ((d^2)/4)

121pi = pi * ((d^2)/4)
121 = (d^2)/4
484 = d^2
d = 22

Answer 9

22cm

Answer 10

HUH ?