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.
Introduce angular bisectors in a triangle and their point of concurrence.
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
Download this geogebra file from this link.
Process (How to do the activity)
- The teacher can use this geogebra file and ask the questions listed below.
- Developmental Questions;
- What type of triangle is this ? Why ?
- Identify the three angles.
- What is an angle bisector ?
- Identify the point of concurrence of angle bisectors ?
- This point, called incentre of the triangle does its position change with the type of triangle ?
- Identify the circle. What is its radius ? What can this radius be called ?
- What is this circle called ?
- What is incentre, inradius and incircle ?
- Question Corner:
- What do you think would be the practical applications of the incentre and incircle ?