Step 1: Measure or record the circumference.

Step 2: Use the relationship between circumference and radius to revise the formula.

NOTE: Circumference C = 2 \pi r

                                     r = \frac{C}{2*\pi}

Step 3: Find the radius of the circle

            EXAMPLE:   r = \frac{C}{2*\pi}

                                 r = \frac{22}{2*\pi} (since \pi = \frac{22}{7} = 3.14)

                                     r = \frac{7}{2}

Step 4: Substitute the radius in the area of the circle formula.

            NOTE: Area of the circle = \pi r^2

Step 3: Square the radius and multiply by \pi. 

          EXAMPLE: Radius r = 14, then

                                 A =   \pi 14^2

                          A =   \frac{22}{7} * 196    ( since  \pi = \frac{22}{7} =3.14)

                             A    = 615.44 cm^2