Area of Circle Formula

Area of Circle

Formula

Summary

The area of a circle is given by mutiplied by the circle constant (tau) multiplied by the radius of the circle squared. The value of is approximately and .

Expression Description
The area of the circle.
The circle constant (tau), where
The radius of the circle.

Usage Notes

The area of a circle is given by mutiplied by the circle constant (tau) multiplied by the radius of the circle squared. For example, to find the area of a circle with a radius of length 5 the formula is:

Area of Circle Radius of 1
Circle of Radius 1

To calculate the area of a circle given a radius of one, set up the equation for the area of the circle and substitute the value of the radius into the equation.

Steps
  1. Substitute the length of the radius into the formula.

  2. Evaluate the exponent expression and simplify.

  3. Substitute the value of into the expression.

  4. Evaluate the multiplication.

  5. The area of a circle of radius is approximately units squared.

Area of Circle Radius of 2
Circle of Radius 2

To calculate the area of a circle given a radius of two, set up the equation for the area of the circle and substitute the value of the radius into the equation.

Steps
  1. Substitute the length of the radius into the formula.

  2. Evaluate the exponent expression and simplify.

  3. Simplify the fraction.

  4. Substitute the value of into the expression.

  5. Evaluate the multiplication.

  6. The area of a circle of radius is approximately units squared.

Area of Circle Radius of 3
Circle of Radius 3

To calculate the area of a circle given a radius of three, set up the equation for the area of the circle and substitute the value of the radius into the equation.

Steps
  1. Substitute the length of the radius into the formula.

  2. Evaluate the exponent expression and simplify.

  3. Substitute the value of into the expression.

  4. Multiply the fraction by the value of .

  5. The area of a circle of radius is approximately units squared.