AMSCO'S Geometry. New York - Rye High School

212 Transformations and the Coordinate PlaneGraphing PolygonsA quadrilateral (a four-sided polygon) can be represented in the coordinateplane by locating its vertices and then drawing the sides connecting the verticesin order.The graph shows the quadrilateral ABCD.yThe vertices are A(3, 2), B(3, 2), C(3, 2)and D(3, 2).1. Points A and B have the same y-coordinateand are on the same horizontal line.2. Points C and D have the same y-coordinateand are on the same horizontal line.3. Points B and C have the same x-coordinateand are on the same vertical line.4. Points A and D have the same x-coordinateand are on the same vertical line.5. Every vertical line is perpendicular toevery horizontal line.1 OA(3, 2)6. Perpendicular lines are lines that intersect to form right angles.Each angle of the quadrilateral is a right angle:mA mB mC mD 90From the graph, we can find the dimensions of this quadrilateral.To find ABand CD, we can count the number of units from A to B or from C to D.AB CD 6Points on the same horizontal line have the same y-coordinate. Therefore,we can also find AB and CD by subtracting their x-coordinates.AB CD 3 (3) 3 3 6To find BC and DA, we can count the number of units from B to C or fromD to A.BC DA 4Points on the same vertical line have the same x-coordinate. Therefore, wecan find BC and DA by subtracting their y-coordinates.BC DA 2 (2) 2 2 41x