# Area of a Regular Polygon 2

__Area of a regular polygon of n sides when the radius r of the inscribed circle is given__

Since

the area of the polygon area of the

But ,

and

Hence, the area of the regular polygon

Also, the perimeter of the polygon

(Using from above)

__Example__:

A regular octagon circumscribed a circle of radius. Find the area of the octagon.

__Solution__:

Here ,

the area of the polygon

the area of the polygon square meters, approximately.