Question

Match the reasons with the statements in the proof to prove DE = EF given that DEF is a triangle by definition and angles 3 and 4 are equal.
Given:
△ DEF
∠3 = ∠4

Prove:
DF = EF


1. If the Two Angles of a Triangle are Equal, then the Sides Opposite those Angles are also Equal
2. Two Angles Supplementary to Equal Angles are Equal to Each Other
3. Exterior Sides are in Opposite Rays
4. Given

∠3 = ∠4
∠1 and ∠3 are supplementary
∠2 and ∠4 are supplementary
∠1 = ∠2
DE = EF
2