# Construction of a triangle with perimeter and base angles

From Karnataka Open Educational Resources

### Objectives

To construct a triangle with perimeter and base angles

### Estimated Time

30 minutes

### Prerequisites/Instructions, prior preparations, if any

Prior understanding of point, lines and angles, elements of triangle, properties of triangle

### Materials/ Resources needed

- Digital : Computer, geogebra application, projector.
- Non digital : Worksheet and pencil
- Geogebra files : “Triangle Construction(Perimeter-base angles)”

Download this geogebra file from this link.

### Process (How to do the activity)

- Use the slider to construct the perimeter
- How do you get the 3 points required for the triangle
- Why is the half angle constructed at each points
- Perpendicular bisectors for the two segment formed due to the intersection of the half angles are constructed
- What do these bisectors mark on the perimeter line
- How is the required triangle formed using this method

**Evaluation at the end of the activity**

- For what values of the angles the triangle is not formed.