What is the answer to this math problem with full work advanced geometry

You will get 25 points an image of a rectangular prism is shown below: part a: a cross section of the prism is cut with a plane parallel to the base. what is the name of the shape created by the cross section? explain your answer. (5 points) part b: if a cross section of the prism is cut perpendicular to the base, what would be the shape of the resulting cross section? explain your answer. (5 points)

Lines a and b are parallel. what is the value of x? -5 -10 -35 -55

Are the corresponding angles congruent? explain why or why not.