Question

Here is an explanation that the angle sum of triangle ABC is 180°.
The reasons for each line are missing.
Give the reasons.
1. Angle A of the triangle = angle PCA
2. Angle B of the triangle = angle QCB
3. Angle PCA + angle C of the triangle + angle QCB = 180°
Hence angle A + angle B+ angle C = 180°​

Answer 1

Step-by-step explanation:

∠PAB + ∠BAC + ∠CAQ = 180°. where PQ line parallel to side BC touching vertex A. ∠PAB = ∠ABC & ∠CAQ = ∠ACB BECAUSE alternate interior angles are congruent..