Students can go through AP Board 9th Class Maths Notes Chapter 7 Triangles to understand and remember the concepts easily.
AP State Board Syllabus 9th Class Maths Notes Chapter 7 Triangles
→ Two line segments are congruent if they have equal length.
→ Two squares are congruent if they have same side.
→ Squares that have same measure of diagonals are also congruent.
→ Two triangles are congruent if they cover each other exactly.
→ If two triangles are congruent then Corresponding Parts of Congruent Triangles (CPCT) are equal.
→ Two triangles are congruent if two sides and the included angle of one triangle are equal to the two sides and included angle of the other triangle (S.A.S. 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 the other triangle (A.S.A. congruence rule).
→ Two triangles are congruent if any two pairs of angles and one pair of corresponding sides are equal (A.A.S.).
→ Angles opposite equal sides of a triangle are equal.
→ The sides opposite to equal angles of a triangle are equal.
→ If three sides of one triangle are respectively equal to the corresponding three sides of another triangle, then the two triangles are congruent (SSS).
→ If in two right triangles the hypotenuse and one side of one triangle are equal to the hypotenuse and one side of the another triangle, then the two triangles are congruent (RHS).
→ In a triangle, of the two sides, side opposite to greater angle is greater.
→ Sum of any two sides of a triangle is greater than the third side.