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

△DEF

∠3 = ∠4

Prove:

DF = EF

1. ∠1 = ∠2
Two Angles Supplementary to Equal Angles are Equal to Each Other
2. DF = EF
Exterior Sides are in Opposite Rays
3. ∠3 = ∠4
Given
4. ∠1 and ∠3 are supplementary

∠2 and ∠4 are supplementary
If the Two Angles of a Triangle are Equal, then the Sides Opposite those Angles are also Equal