A big dump truck delivers a gravel to the construction site the dump truck has a rectangular bed that is 3 m wide and 4 m long

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

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me