# Thread: Probably Stupid, but trouble with Proofs.

1. ## Probably Stupid, but trouble with Proofs.

it's a two-column proof problem...
says prove Line AD is congruent with line BC.

Statement | Proof
AD parallel with BC | given
DC parallel AB | given
??

using the given,which angles are congruent considering the two parallel lines are cut by the transversal? and what is the specific term for that anyway?

Thanks for any help, guys.

2. Originally Posted by Savior_Self
it's a two-column proof problem...
says

Prove: $\overline{AD}\cong \overline{CB}$

STATEMENTS...............................REASONS

(1) $\overline{AD}\parallel\overline{BC}\ \ and \ \ \overline{DC}\parallel\overline{AB}$...............GIVEN

(2) $\angle ACD \cong \angle CAB \ \ and \ \ \angle DAC \cong \angle BCA$.............If two parallel lines are cut by a transversal, alternate interior angles are congruent.

(3) $\overline{AC}\cong\overline{AC}$........Reflexive property of congruence.

(4) $\triangle ADC \cong \triangle CBA$..........ASA

(5) $\overline{AD}\cong\overline{CB}$..........CPCTC

Originally Posted by Savior_Self
Using the given,which angles are congruent considering the two parallel lines are cut by the transversal? and what is the specific term for that anyway?

Thanks for any help, guys.
I guess you're referring to step 2 above.

3. Ah, now I understand. Much thanks.