7.1 INTRODUCTION:

  • Two congruent figures have exactly the same shape and size.
  • If two  triangles are congruent, then their corresponding parts are equal.
  • Angles opposite to equal sides of a triangle are equal.
  • Sides opposite to equal angles are equal.
  • The measure of each angle of an equilateral triangle is 60°.
  • In a triangle, the sum of any two sides is always greater than the third side.
  • In a triangle, the angle opposite to the longer side is bigger.
  • In a triangle, the side opposite to the greater angle is the longer.