Draw the triangle L M N of any convenient size. M N may be made 3 1/4 inches, L M, 2 3/4 inches, and L N, 3 1/2 inches. Bisect the angles M L N and L M N by the method used in Problem 8. The bisectors M I and L J intersect at 0, which is the center of the inscribed circle. The radius of the circle is equal to the perpendicular distance from 0 to one of the sides.

Proof

The point of intersection of the bisectors of the angles of a triangle is equally distant from the sides.