The formula for the area of a circle:
\(\pi*r^2\), where r is radius of circle
\(\pi*r^2=19.625|:\pi\)
\(r^2=\frac{19.625}{\pi}|\sqrt{}\)
\(r=\sqrt{\frac{19.625}{3.14}}=2.5\)
The formula for the circumference of a circle:
\(2*\pi*r\), where r is radius of circle
\(2*\pi*r=2*3.14*2.5=15.7\)units squared
As can be seen easily calculated radius of the circle first, and then used this to calculate the circumference of the circle.
