Watch Sal classify a quadrilateral as a square, rhombus, rectangle, parallelogram, or trapezoid given its four vertices.
Geometry problems on the coordinate plane is a free educational video by Khan Academy.It helps students in grades 9,10,11,12 practice the following standards HSG.GPE.B.4.
1. HSG.GPE.B.4 : Use coordinates to prove simple geometric theorems algebraically. For example, prove or disprove that a figure defined by four given points in the coordinate plane is a rectangle; prove or disprove that the point (1, √3) lies on the circle centered at the origin and containing the point (0, 2)..