Question

A circle has the area of 19.625 units squared...
pi is 3.14
what is the circumference?

Answer 1

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=(19.625)/(\pi)|\sqrt{}`

`r=\sqrt{(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.