a) Quadrilaterals have two diagonals...you can calculate both but you should know what "slope" is first.
b) You know the endpoints...use Pythagorean theorem to find length and width.
c) Easy once you know answers to part b).
"Slope" is basically the "steepness" of a line or function. Basically, the steeper the line, the greater the slope (actually, absolute value of the slope). Horizontal lines have a slope of zero, and vertical lines have undefined slope. The slope between two points and is .