Theorem of triangle I Prove theorems about triangles I cbse maths I part- #3
2018-03-21 21 Dailymotion
Triangles: Class 9 cbse maths. Theorem-1 The sum of the angles of a triangle is 180 degree. Theorem-2 If a side of a triangle is produced, then the exterior angle so formed is equal to the sum of the two interior opposite angles.
