Jamie is writing a proof of the theorem stated below.

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

He first drew the figure shown below.

Question

Jamie is writing a proof of the theorem stated below.
 
Theorem: The sum of interior angles of a triangle is 180°.
 
He first drew the figure shown below.

anonymous · Answer

attachment

anonymous · Answer

Which theorem will he most likely use in the proof?

anonymous · Answer

Vertical angles are congruent.
		Supplements of congruent angles are congruent.
		Alternate interior angles formed by parallel lines and their transversal are congruent.
		If two angles of a triangle are congruent, the sides opposite these are congruent.

anonymous · Answer

Alternate interior angles formed by parallel lines and their transversal are congruent.

anonymous · Answer

use parallel line theorems
angles 1 are alternate
angles 2 are corresponding