NCERT Class 9 Solutions: Triangles (Chapter 7) Exercise 7.2 – Part 4

Interior Angle

Give interior angle of two parallel line when two lines are cut by a third line lthen made a,b,c,d angle

Give Interior Angle

Give interior angle of two parallel line when two lines are cut by a third line lthen made a,b,c,d angle

When two lines are cut by a third line (transversal), then the angles formed inside the lines are called Interior Angles.

Q-7 ABC is a right angled triangle in which A=90° and AB=AC . Find B and C.

Solution:

Segment f Segment f: Segment [A, B] Segment g Segment g: Segment [B, C] Segment h Segment h: Segment [C, A] A text1 = "A" B text2 = "B" C text3 = "C"

ABC Is a Right Angled Triangle

ABC is a right angled triangle in which ∠A = 90° and AB = AC

Given, A=90° and AB=AC

  • Now, AB=AC B=C (Angles opposite to the equal sides are equal.)

  • Now, A+B+C=180° (Sum of the interior angles of the triangle.) 90°+2B=180° ( B=C) 2B=90°B=45°

  • Thus, B=C=45°

Q-8 Show that the angles of an equilateral triangle are 60° each.

Solution:

Segment f Segment f: Segment [A, B] Segment f Segment f: Segment [A, B] Segment g Segment g: Segment [B, C] Segment g Segment g: Segment [B, C] Segment h Segment h: Segment [C, A] Segment h Segment h: Segment [C, A] A text1 = "A" B text2 = "B" C text3 = "C"

ABC Be an Equilateral Triangle.

ABC be an equilateral triangle each of angle is 60

Give, ABC be an equilateral triangle. BC=AC=AB (Length of all sides is same) A=B=C (Sides opposite to the equal angles are equal.)

  • Also, A+B+C=180° (Sum of the angles of the triangle.) 3A=180° ( A=B=C ) A=60°

  • Therefore, A=B=C=60°

  • Thus, the angles of an equilateral triangle are 60° each.

Explore Solutions for Mathematics

Sign In