Given: BC⎯⎯⎯⎯⎯ || DE⎯⎯⎯⎯⎯, and ∠GAC≅∠AFD (figure).

Prove: GH←→⊥DE←→

Statement Reason
1. ∠GAC≅∠AFD given
2. ∠GAC≅∠AFE For parallel lines cut by a transversal, corresponding angles are congruent.
3.
4. ∠AFD and ∠AFE are
supplementary. Linear Pair Theorem
5. m∠AFD = m∠AFE = 90° If two congruent angles are supplementary, then each angle is a right angle.
6. GH←→⊥DE←→ definition of perpendicular lines

Question

Given: BC⎯⎯⎯⎯⎯ || DE⎯⎯⎯⎯⎯, and ∠GAC≅∠AFD (figure).

Prove: GH←→⊥DE←→

Statement	Reason
1. ∠GAC≅∠AFD	given
2. ∠GAC≅∠AFE	For parallel lines cut by a transversal, corresponding angles are congruent.
3. 	 
4. ∠AFD and ∠AFE are
    supplementary.	Linear Pair Theorem
5. m∠AFD = m∠AFE = 90°	If two congruent angles are supplementary, then each angle is a right angle.
6. GH←→⊥DE←→	definition of perpendicular lines

anonymous · Answer

What's the missing step?