
That is a sufficient condition for this object to be a parallelogram. So, we have proven that opposite sides of quadrilateral #PQRS# are parallel to each other. #(y_S-y_R)/(x_S-x_R)=(y_C+y_D-y_C-y_B)/(x_C+x_D-x_C-x_B)=#Īs we see, the slopes of #PQ# and #RS# are the same.Īnalogously, slopes of #PR# and #QS# are the same as well. In this lesson, you will use coordinate systems to prove geometric theorems. For this, let's calculate the slope of both and compare them. Geometric Proofs using Coordinate Systems Objective. Let's prove that #PQ# is parallel to #RS#.


Let four points #A(x_A,y_A)#, #B(x_B,y_B)#, #C(x_C,y_C)# and #D(x_D,y_D)# are vertices of any quadrilateral with coordinates given in parenthesis. Midpoints of sides of any quadrilateral form a parallelogram. geometry reasoning and proof the segment addition.

In some cases to prove a theorem algebraically, using coordinates, is easier than to come up with logical proof using theorems of geometry.įor example, let's prove using the coordinate method the Midline Theorem that states: Coordinate geometry mathematics 1, Answers to geometry unit 1 practice. In other words, we use numbers (coordinates) instead of points and lines. 5-3 Practice Form K Bisectors in Triangles Coordinate Geometry Find the coordinates of the circumcenter of each triangle. Coordinate proof is an algebraic proof of a geometric theorem.
