Summary
With the help of this activity, we have learnt that:
If a side of a triangle is extended, then the exterior angle so formed is equal to the sum of the two interior opposite angles.
When the exterior angle formed at one of the sides of a triangle becomes equal to the sum of the two interior opposite angles then the arm of the exterior angle which is outside the triangle is in a straight line with that side of the triangle which it meets. In other words, we can say that a side of the triangle has been extended to form this exterior angle.
