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If the Angles A, B and C of δAbc Satisfy the Relation B − a = C − B, Then Find the Measure of ∠B.

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Question

If the angles A, B and C of ΔABC satisfy the relation B − A = C − B, then find the measure of ∠B.

Answer in Brief
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Solution

In the given ΔABC

∠A, ∠B and ∠C satisfy the relation B - A = C - B

We need to fine the measure of ∠B.

As,

B - A = C - B

B + B = C + A

2B = C + A

2B - A = C       ........(1)

Now, using the angle sum property of the triangle, we get,

A + B + C = 180°

2B - A + A +B = 180° (Using 1)

3B = 180° 

`B = (180°) / 3`

= 60°

Therefore, ∠B = 60°

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Chapter 11: Triangle and its Angles - Exercise 11.3 [Page 24]

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R.D. Sharma Mathematics [English] Class 9
Chapter 11 Triangle and its Angles
Exercise 11.3 | Q 9 | Page 24

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