Given: e ll f and g is transversal prove: ∠1 ≅ ∠8

given that e ii f and g is a transversal, we know that ∠4 ≅ ∠5 by the alternate interior angles theorem. we also know that ∠1 ≅ ∠4 and ∠5 ≅ ∠8 by the therefor, ∠1 ≅ ∠8 by the substitution property.

a. corresponding angles theorem

b. alternate interior angles theorem

c. vertical angles theorem

d. alternate exterior angles theorem