Question 175149
Your question is difficult to answer because I don't know hom much math you know.  This being the case I will suggest using a "brute force" method.

Plot the 4 points on graph paper.  Draw lines to connect the points.  Measure the angles between adjacent lines.  With this information, look for perpendicular and/or parallel lines.  

After you have determined the number of parallel and/or perpendicular lines, review the definitions of the different types of quadrilaterals (square, rectangle, parallelogram, rhombus, etc) to see which definition matches the conditions you have determined exist with the geometric figure that you hace drawn.

I hope that this helps or at least gives you some ideas as to how to move forward.