A circle is 13cm What is the radius and diameter of the following circle?

I think you mean the area of the circle is 13 cm, In that case, let's use the formula to solve it!

d ~ 4.04

r ~ 2.02.

Step-by-step explanation:

Basically since we know the formula is pi (3.14) * r * r = A, we can divide A by 3.14.

Let's set this up!

r^2 * 3.14 = 13

Divide both sides by 3.14

And we get

r^2 ~ 4.1

Now, let's square root both sides and get

r ~ 2.02.

since d = r * 2, we can do

d ~ 2.02 (2)

d ~ 4.04