Find the slope of a line that passes through the points (3, 1) and (9,8

Line u passes through points (-52, -18) and (-29, 53). line v passes through points (90, 33) and (19, 56). are line u and line v parallel or perpendicular?

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)

Aladder that is 20 ft. long against the side of a building. f the angle formed between the ladder and the ground is 75 degrees, how far is the bottom of the ladder from the base of the building?