Question

in triangle ABC the measure of angle A is equal to the sum of the measure of angle B and angle C.Also the ratio of angle B and Angle c is 4:5 . from the measure of angles of the triangle











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Answer 1

Answer:

Given:

∠B+∠C= ∠A

∠B:∠C= 4:5

To find:

Measure of all angles

Solution:

Let m∠B= 4x

      m∠C=5x

Since ∠A=∠B+∠C

Therefore, ∠A= 4x + 5x

                       = 9x

Also, since measure of all angles of a triangle sum up to 180°

Therefore, ∠A+∠B+∠C=180°

                9x + 4x + 5x= 180

                18x=180

                x= 180/18

                x=10°

Since x=10°

Therefore ∠A=9x=9×10= 90°

                 ∠B=4x=4×10=40°

                 ∠C=5x=5×10=50°