# Construction of a triangle with side, angle and difference of other two sides

From Karnataka Open Educational Resources

Difference of two sides and an angle are parameters known, this construction of triangle follows SAS congruence rule.

### Objectives

To construct a triangle with side, angle and difference of other two sides

### 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(1side-1angle-difference of other 2 sides)”

Download this geogebra file from this link.

### Process (How to do the activity)

- Use the slider to set the base and the given angle
- The difference of the other two sides is marked using the slider
- Follow the steps for construction – step1, step2
- Students can vary the sliders to observe the changes reflected in the triangle.

**Evaluation at the end of the activity**

- When does the triangle not form?