Question

Amanda is writing a proof for the theorem stated below.

Theorem: The sum of interior angles of a triangle is 180°.

She first drew the figure shown below.

Answer 1

Which theorem will she most likely use in the proof?

Supplements of congruent angles are congruent.

If two angles of a triangle are congruent, the sides opposite these are congruent.

All straight angles are congruent.

Corresponding angles formed by parallel lines and their transversal are congruent.

Answer 2

for rpq=tql Corresponding angles formed by parallel lines and their transversal are congruent.

Answer 3

for prq=tqr When a transversal cuts two parallel lines, alternate angles are equal in size.

Answer 4

then u have 3+2+1 = 180 which proof the theorem