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