## Class 9 Maths Chapter 7 Theorems Triangles

- Theorem 7.1 Class 9 (ASA congruence rule) Two triangles are congruent if two angles and the included side of one triangle are equal to two angles and the included side of other triangle.
- Theorem 7.2 Class 9 Angles opposite to equal sides of an isosceles triangle are equal.
- Theorem 7.3 Class 9 The sides opposite to equal angles of a triangle are equal.
- Theorem 7.4 Class 9 (SSS congruence rule) If three sides of one triangle are equal to the three sides of another triangle, then the two triangles are congruent.
- Theorem 7.5 Class 9 (RHS congruence rule) If in two right triangles the hypotenuse and one side of one triangle are equal to the hypotenuse and one side of the other triangle, then the two triangles are congruent.
- Theorem 7.6 Class 9 If two sides of a triangle are unequal, the angle opposite to the longer side is larger (or greater).
- Theorem 7.7 Class 9 In any triangle, the side opposite to the larger (greater) angle is longer.
- Theorem 7.8 Class 9 The sum of any two sides of a triangle is greater than the third side.