1. Graph the rectangle using the vertices. Label the rectangle vertices as A, B, C and D clockwise starting with the one in the upper lefthand corner. For example, given the vertices
http://www.ehow.com/how_8450142_arearectanglever...

suma nimo. pangita.a.
http://wiki.answers.com/Q/What_is_vertical_rectang...

There are four vertices (corners) in a rectangle. You can prove tha...
http://www.chacha.com/question/whatareverticeso...

I'm not sure if this will help but a line that is perpendicular to a certain line is that line's slope(m) times 1/m.
http://answers.yahoo.com/question/index?qid=200805...
