
Spencer G. answered 05/13/23
Tutor
New to Wyzant
Fresh Math Major Grad, Incoming Grad Student/TA
Note that L1 is a transversal of parallel lines T1 and T2, and T2 is a transversal of parallel lines L1 and L2. We can use what we know about corresponding and vertical angles, along with the transitivity of congruence, to complete the proof:
- ∠x ≅ ∠1 (These are corresponding angles).
- ∠1 ≅ ∠2 (These are vertical angles).
- ∠2 ≅ ∠y (These are corresponding angles).
- ∠1 ≅ ∠y (By lines 2 and 3, and the transitivity of angle congruence).
- ∠x ≅ ∠y (By lines 1 and 4 and the transitivity of angle congruence).

Spencer G.
Refresher on transitivity: if "=" denotes an equivalence relation, then x=y and y=z implies x=z.05/13/23