  Math Central - mathcentral.uregina.ca  Quandaries & Queries    Q & Q    Topic: negative reciprocal slopes   start over

One item is filed under this topic.    Page1/1            Proving a quadrilateral is a rectangle 2007-07-14 From Sonja:I was having this discussion with another teacher and we need a third opinion. When you are trying to prove a quadrilateral is a rectangle which method should you use: Prove the shape is a parallelogram by doing slope 4 times by stating that parallel lines have equal slopes. Then proving a right angle by stating that perpendicular lines have negative reciprocal slopes. Doing the slope 4 times and stating that the shape is a rectangle because opposite sides are parallel because of equal slopes and it contains a right angle because of negative reciprocal slopes. I guess the real question is do you have to first state that the shape is a parallelogram?Answered by Stephen La Rocque.      Page1/1    Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.    about math central :: site map :: links :: notre site français