Figures in the Coordinate Plane (Sec 9-1) Answers

Step 1: Find the slope of AB. The slope of AB is .

Step 2: Find the slope of DC. The slope of DC is .

Step 3: Find the slope of BC. The slope of BC is .

Step 4: Find the slope of AD. The slope AD is .

The quadrilateral is a trapezoid because .

To determine if it is a parallelogram, use the converse of the parallelogram diagonal theorem. This states that if the diagonals , then the quadrilateral is a parallelogram.

The midpoint of HJ is and the midpoint of IK is (2, 2).

Therefore, HIJK is a parallelogram because the diagonals , which means they bisect each other.