Perpendicular bisectors and circumcenter of a triangle

Circumcentre for different types of triangles is investigated with this activity and this further explores several geometric relationships related to the circumcentre and perpendicular bisectors.

Objectives

Introduce perpendicular bisectors in a triangle and their point of concurrence.

Estimated Time

30 minutes.

Prerequisites/Instructions, prior preparations, if any

Ensure that circles, triangles, perpendicular bisectors and their constructions are covered

Materials/ Resources needed

Digital resources: Laptop, geogebra file, projector and a pointer.

Geogebra files: Concurrency of perpendicular bisectors.ggb

Download this geogebra file from this link.

Process (How to do the activity)

1. Project the geogebra file and ask the following questions.

• Developmental Questions:

1. What is a perpendicular bisector ?
2. How do you construct it ?
3. Identify the point of intersection of perpendicular bisectors in different triangles.
4. What is circumcircle ?

• Evaluation:

1. How is circumradius determined ?
2. What parts of the circle is circumcircle touching ?

• Question Corner:

1. What are the practical applications of determining the circumcircle ?