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Angles A, B, C of a Triangle Abc Are Equal to Each Other. Prove that δAbc is Equilateral.

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Question

Angles A, B, C of a triangle ABC are equal to each other. Prove that ΔABC is equilateral. 

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Solution

Given that angles A,B,C of a triangle ABC equal to each other.
We have to prove that ΔABC is equilateral We have, ∠A = ∠B =∠C
Now, 

[Opposite sides to equal angles are equal] 

and ∠B = ∠C ⇒ AC = AB 

From the above we get 

AB= BC =AC  

⇒ ΔABC is equilateral 

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Chapter 12: Congruent Triangles - Exercise 12.3 [Page 47]

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RD Sharma Mathematics [English] Class 9
Chapter 12 Congruent Triangles
Exercise 12.3 | Q 5 | Page 47

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