1. the structure of the supports for the hill consists of steel beams that

run parallel and perpendicular to one another. the endpoints of the

beam shown by bc are (0, 150) and (120,0). the endpoints of the beam

shown by ad are (0, 125) and (100, 0).

a. verify and explain why the two beams are parallel.

b. if zdab = 125°, what is the measure of zcba? justify your

reasoning

a) Parallel for both line segments have the same slope = -5/4

b)  55º

Step-by-step explanation:

a) To verify the parallelism of these line segments, It's necessary to find the slope of each one. Parallel lines share the same slope value:

b) If ∠DAB = 125°, what is the measure of ∠CBA? Justify your reasoning.

Those beams do not form a parallelogram because:

Using the formula of distance between those points

So this is a trapezoid.  And two adjacent angles within a trapezoid are supplementary, so If ∠DAB = 125º then 180 - ∠CBA=55º