Question

prove that the Sum of the internal angle of a triangle is 180 degree

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Answer 1

Answer:

the figure is not shown yet.

Answer 2

Prove that the sum of all interior angles of a Δ is 180

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Easy

Solution

verified

Solution:-

Consider △PQR with angles ∠1,∠2 and ∠3

Draw a line XY passing through P parallel to QR

For lines XY and QR with transversal PQ

∠2=∠4 (alternate angles)

For lines XY and QR with transversal PR

∠3=∠4 (Alternate angles)

Also, for line XY

∠1+∠4+∠5=180

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(linear pair)

∠1+∠2+∠3=180

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Hence, sum of all angles of a triangle is 180

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solution

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