Question

Prove that the sum of the measures of the interior angles of a triangle is 180°

Answer 1

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

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°   [Proved].

Answer 2

Answer:

the answer is 180 degree