# Construction of a triangle with 3 sides

Investigating formation of a unique triangle with the given parameters as the three sides. Constriction follows SSS congruence rule.

### Objectives

• To construct a triangle for given 3 sides
• To show formation of different types of triangles when sides are varied
• To show changes in angles when sides are varied.
• To show possibility of formation of a triangle

30 minutes

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

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

### Process (How to do the activity)

• Use the geogebra file to demonstrate how to construct a triangle if three sides of a triangle are given
• Students can be asked for a given any one side how many triangles are possible.
• How will you  draw the second side? Where will you fix the position of the second side?
• How will you draw the third side? How can you fix the position third side?
• For what measurement of sides the triangle is not possible.
• Vary the sliders to observe the changes reflected in the triangle.
• Make different types of triangles with respect to  sides by changing the sliders.
• Challenge them to make
• Isosceles right angled triangle,
• Equilateral triangle including right angle or obtuse angle
• Note the measure of sides in the worksheet

Work sheet

 Side1 Side2 Side3 Side1+ Side2 > Side 3 Side2 + Side 3 > Side 1 Side1+ Side3 > Side 2 YourObservations . .

Evaluation at the end of the activity

• Can you construct a triangle for any given sides?
• For given 3 sides how many triangles are possible?
• Will the triangle formed change if the order of sides taken for construction is changed?