Construction of a triangle with two angles and included side

Objectives

 * To construct a triangle given two sides and an angles
 * To understand the given angle should be included angle when two sides are given

Estimated Time
20 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-2angles)”

Process (How to do the activity)
Evaluation at the end of the activity
 * For given 2 angles, if the angles add to 180o, can you construct the triangle?
 * Is it possible to construct a triangle with only 2 given angles. What is the other parameter required for construction.
 * If any one side is specified, along with 2 angles how many triangles are possible.
 * If the side given is an included side, how many triangles are possible.
 * Why should the given side be included side?
 * For the given A, A and S are the triangles AAS,  ASA and SAA congruent triangles.