Hey, I'm dumb and need help.

Prove that opposite sides of a parallelogram are congruent. Be sure to create and name the appropriate geometric figures. (10 points)

(The blanks below need to be filled in)

Let ABCD be a parallelogram. By definition of a ________, side AB is parallel to side CD and side BC is parallel to side DA. Construct diagonal BD using a straightedge. ∡ABD is congruent to ∡BDC by the _____ _____ ______ Theorem. By the same theorem, ∡CBD is congruent to ∡ADB. Segment BD is congruent to itself by the _____ Property of Equality. Therefore, ABD is congruent to CDB by _____ and opposite sides of parallelogram ABCD are congruent by _____.

Thank ye kindly.