Angular bisectors and incenter of a triangle

The intersecting point of three lines which are the bisectors of three angles of a triangle that is the incenter and it's properties are examined.

Objectives
Introduce angular bisectors in a triangle and their point of concurrence.

Estimated Time
40 minutes.

Prerequisites/Instructions, prior preparations, if any
Angles, angle bisectors, concurrent lines and triangles should have been covered.

Materials/ Resources needed
Digital resources: Laptop, projector and a pointer.

Geogebra file: Concurrency of angular bisectors.ggb

Process (How to do the activity)

 * 1) The teacher can use this geogebra file and ask the questions listed below.
 * Developmental Questions;
 * 1) What type of triangle is this ? Why ?
 * 2) Identify the three angles.
 * 3) What is an angle bisector ?
 * 4) Identify the point of concurrence of angle bisectors ?
 * 5) This point, called incentre of the triangle does its position change with the type of triangle ?
 * 6) Identify the circle. What is its radius ? What can this radius be called ?
 * 7) What is this circle called ?
 * Evaluation:
 * 1) What is incentre, inradius and incircle ?
 * Question Corner:
 * 1) What do you think would be the practical applications of the incentre and incircle ?