The diagonals of parallelogram defg intersect at h. what congruence statements can you make about the parallelogram?

Anyone know? will mark brainliest if correct!

Sketch one cycle if the cosine function y=2cos2theta

In the following diagram it is given that dec, ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2