Question

prove that sum of the measure of angle of triangle is 180°​

Answer 1

Answer:

So, the angle sum ∠A + ∠B + ∠C is equal to the angle sum ∠A' + ∠B' + ∠C'. The three angles A', B', and C' form together a straight angle (they are along the line l). So, their angle sum is 180°.

Answer 2

$\huge\Large\underline\mathtt\pink{Tô Prövë :-}$

sum of the measure of angle of triangle is 180°

$\huge\Large\underline\mathtt\purple{នƬ៩ᖰ ᖲƴ នƬ៩ᖰ ន០ɭuƬɨ០n :-}$

• 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°  

[Proved]