This section is from the book "Modern Shop Practice", by Howard Monroe Raymond. Also available from Amazon: Modern Shop Practice.

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.

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

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