You can use GeoGebra to find the incircle and incenter of a triangle.
GeoGebra Instruction 1
- 1.
- Open
Algebra ViewandGraphics Viewunder
Viewin
Menu. - 2.
- Make a triangle with the vertices , , and by using the tool
Polygon
. Then, you need to click on three points in Graphics Viewwhere you want the vertices of the triangle to be. Finally, complete the triangle by clicking on the point that you started with. - 3.
- Click
Angle Bisector
by first clicking tool number 4, then tool number 4 in the drop-down list. - 4.
- Construct the angle bisector of by clicking on , , and in that order. To construct the angle bisector of , click on , , and in that order. Finally, click on , , and to construct the angle bisector of .
- 5.
- Click
Intersect
by first clicking tool number 4, then tool number 4 in the drop-down list, and use it to find the point of intersection between two angle bisectors. The point is the incenter. - 6.
- Click
Circle with Center through Point
, and construct a circle using the incenter as the center. Expand it so that the circle touches one side of the triangle. You can then see that the circle actually touches all sides of the triangle. You’ve found the incircle!
