Learn the relationship between the radius, diameter, and circumference of a circle.

If we say the circumference is 1600 pi, and this is equal to pi times the diameter, we can just divide both sides by pi to get the diameter, which is going to be 1600.

*To find the diameter, measure the circle from its left-right points [divide the circle in half and measure the line you made, make sure the line is straight]. Suppose you get 10in, that is your diameter.

The area of a circle is pi times the radius squared (A = π r²). Learn how to use this formula to find the area of a circle when given the diameter.

A circle has a circumference of 113.04 units. What is the diameter of the circle? Use 3.14 for π and enter your answer as a decimal.

Just divide circumference by pi! It's easy to see this with the circumference formula: C = pi*d => d = C/pi.

The circumference of a circle is its perimeter. To calculate it, use the formula 2πr, where r is the radius of the circle. The area of the circle can be found by the formula πr^2.

The length is given, and the width can be calculated using the formula for circumference of a circle. Once you have both values, just multiply l x w to find the area, then add it to the area of the two …

The radius of a sphere is half its diameter. So, to calculate the volume of a sphere given the diameter of the sphere, you can first calculate the radius, then the volume.

Formula for area of a circle Congratulations, you've just shown that when the radius of a circle is r , then the area of a circle is π ⋅ r ⋅ r , which we often write as π r 2 !