R s aggarwal solutions mathematics class 9 Solutions for Chapter 8 triangles

In △ ABC, if ∠B = 76 and ∠C = 48, find ∠A.

In △ ABC, if 3 ∠A = 4 ∠B = 6 ∠C, calculate ∠A, ∠B and ∠C.

In △ ABC, if ∠A + ∠B = 108 and ∠B + ∠C = 130, find ∠A, ∠B and ∠C.

In △ ABC, if ∠A + ∠B = 125 and ∠A + ∠C = 113, find ∠A, ∠B and ∠C.

In △ PQR, if ∠P – ∠Q = 42o and ∠Q – ∠R = 21o, find ∠P, ∠Q and ∠R.

The sum of two angles of a triangle is 116o and their difference is 24o. Find the measure of each angle of the triangle.

Two angles of a triangle are equal and the third angle is greater than each one of them by 18. Find the angles.

Of the three angles of a triangle, one is twice the smallest and another one is thrice the smallest. Find the angles.

If one angle of a triangle is equal to the sum of the other two, show that the triangle is right angled.

If each angle of a triangle is less than the sum of the other two, show that the triangle is acute angled.

In the given figure, side BC of △ ABC is produced to D. If ∠ACD = 128o, and ∠ABC = 43o, find ∠BAC and ∠ACB.

Calculate the value of x in each of the following figures.

(i)

Calculate the value of x in the given figure.

In the given figure, AD divides ∠BAC in the ratio 1: 3 and AD = DB. Determine the value of x.

If the sides of a triangle are produced in order, prove that the sum of the exterior angles so formed is equal to four right angles.

In the given figure, AM ⊥ BC and AN is the bisector of ∠A. If ∠ABC = 70o and ∠ACB = 20o, find ∠MAN.

In the given figure, BAD || EF, ∠AEF = 55 and ∠ACB = 25, find ∠ABC.

In the given figure, AB || DE and BD || FG such that ∠ABC = 50o and ∠FGH = 120o. Find the values of x and y.

In the given figure, AB || CD and EF ⊥ AB. If EG is the transversal such that ∠GED = 130o, find ∠EGF.