Problema Solution

The perimeter of a semicircle is doubled when the radius is increased by 5. Find the radius of the semicircle.

Answer provided by our tutors

Let the radius of the semicircle is x. Then its perimeter is pi*x.

When the radius is x+5 the perimeter is pi*(x+5)

So pi*(x+5)=2*pi*x so x+5=2x, so x=5