How do you figure out the surface area of a circle?

The radius of a normal circle is always one-half of the diameter. Multiply the radius by itself to square it. For example, if your radius was 6 cm, your radius squared would be 36 cm squared. Multiply the result you get from Step 3 by pi. read more

Use the equation obtained in step 2 to calculate the area of a circle with a known radius. A circle with a radius of 2 has an area of A = Pi(r^2) = Pi(2^2) = 4 x Pi, or approximately 12.57. Convert the equation in step 2 to calculate the area of a circle from its diameter. Since 2r = d is an unequal equation, both sides of the equal sign must be balanced. read more

Surface Area = 2(pi r 2) + (2 pi r)* h In words, the easiest way is to think of a can. The surface area is the areas of all the parts needed to cover the can. That's the top, the bottom, and the paper label that wraps around the middle. You can find the area of the top (or the bottom). That's the formula for area of a circle (pi r 2). read more

How to Calculate the Area of a Circle. A common problem in geometry class is to have you calculate the area of a circle based on provided information. You need to know the formula for finding the area of a circle, A=\pi r^2. read more