Construction #11
Inscribe a circle in a triangle
To see a video of Mr. Ochs doing examples
Mr Ochs Video To see and example done in flash click on a link below Math Open Ref Math is Fun 

Given a triangle, inscribe a circle in the triangle.
Construct the inscribed circle of triangle ABC.
1) Construct 2 angle bisectors of the triangle and extend them to intersect each other.
2) From the point of intersection of the angle bisectors construct a perpendicular to one of the sides of the triangle.
2) Take the compass and place the pointer on the point of intersection in step1, then set the radius equal to the distance of the perpendicular constructed in step 2.
3) With this new radius draw a circle inside the triangle. (it should be tangent with all 3 sides of the triangle
NOTE: The circle is not always going to be tangent with all the sides but it should be close!
Construct the inscribed circle of triangle ABC.
1) Construct 2 angle bisectors of the triangle and extend them to intersect each other.
2) From the point of intersection of the angle bisectors construct a perpendicular to one of the sides of the triangle.
2) Take the compass and place the pointer on the point of intersection in step1, then set the radius equal to the distance of the perpendicular constructed in step 2.
3) With this new radius draw a circle inside the triangle. (it should be tangent with all 3 sides of the triangle
NOTE: The circle is not always going to be tangent with all the sides but it should be close!