how to plot quadrilaters on a graph
You mean plot quadrilaterals, right?
To plot quadrilaterals, you must have four points.
For example, let's have these points and labeled them as A(1,2), B(3,6), C(12,6) and D(10,2). The first numbers on these ordered pairs are the x-coordinates and the others are the y-coordinates. To plot each point on the rectangular coordinate. Locate first the first number on the x-axis or the horizontal plane then from that move upwards (if number is +) or downwards (if number is -) n units depending on second number. After plotting each point, you connect point A and B, B and C, C and D, and D and A.