Here we will answer the following three questions. a) What is 100Pi? (What is 100π?), b) What is the area of a circle if the radius is 100?, and c) What is the circumference of circle if the radius is 100?

**100π**is another way of writing 100 times Pi (100 x 3.14). Therefore, the answer to our first question is:

**100π = 314.16**

**Area:**Next, we will calculate the area of a circle if the radius is 100. The formula for the area of a circle is πr

^{2}, which means that the area of a circle with a radius of 100 is:

**π100**

^{2}= 31415.93**Circumference:**Finally, we will calculate the circumference of a circle if the radius is 100. The formula for the circumference of a circle is 2πr, which means that the circumference of a circle with a radius of 100 is:

**2π100 = 628.32**

Note: π or Pi has an infinite number of decimals. For our calculations on this page with a radius of 100, we used Pi with eleven decimals as 3.14159265358 and then we rounded all our answers to two decimals.

Helpful Definitions:

**Radius:**The distance between the center of a circle to the edge of the circle. In our example on this page it was 100.

**Diameter:**The distance between one side of a circle to the exact opposite side of the circle. This is the same as 2 times radius. (For example, if the radius is 100, then the diameter must be 200.)

**Pi:**The ratio of a circle's circumference to its diameter. This is a fixed number regardless of circle size.

We used the following formulas on this page, where A is Area of circle, C is Circumference of circle, and r is radius:

A = πr

^{2}

C = 2πr

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