Question

Prove that the sum of the angles of a triangle is 180º.

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Answer 1

In order to prove that the sum of angles of a triangle is 180, you must know the theorems of angles of a triangle.

We know that,  alternate interior angles are of equal magnitude.

This'll help us get the answer. Let us assume a triangle ABC. Now we have to substitute the angles.

∠PAB + ∠BAC + ∠CAQ = 180°. where PQ line parallel to side BC touching vertex A.

∠PAB = ∠ABC & ∠CAQ = ∠ACB BECAUSE alternate interior angles are congruent..

Hence we get, ∠ABC + ∠BAC + ∠ACB = 180°

Hence proved

have a nice day

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Answer 2

here is ur solution mate...

Draw a triangle ABC.

Draw a perpendicular line AD.

In triangle ABD

AD =90°

(one angle is of 90°in right angle triangle)ABD

by using Pythagoras theoram

we can prove that ABD is a right angled triangle

In triangle ACD

by using Pythagoras theoram we can find this also as a right angled triangle.

ABC is congruent to ABD

hence proved.

hope it helps you....