This is the third part of the Geometer’s Sketchpad Essentials Series. In this tutorial, we are going to construct the incircle of a triangle. In doing so, we are going to learn how to use the *Compass tool* and construct *Angle bisectors*.

**Step by Step Instructions**

1.) Using the **Segment tool**, construct a triangle.

2.) Select the **Text tool** and click each vertex to reveal their names. GSP will name the triangle *ABC*.

3.) To construct the angle bisector of angle *A*, deselect all the objects, and then click the vertices in the following order: *B*, *A*, *C* (or *C*, *A*, *B*).

4.) Next, click the **Construct** menu from the menu bar and choose **Angle Bisector**. This will produce a ray bisecting angle *A*. Now, construct the the angle bisector for angle *B*.

5.) To intersect the two rays, deselect all the objects, click the two rays, and choose **Intersection** from the **Construct** menu. The intersection of the two rays will be the center of our circle. Continue reading