### Home > INT2 > Chapter 7 > Lesson 7.1.2 > Problem7-31

7-31.

On graph paper, plot and connect the points $A(1,1),B(2,3),C(5,3),$ and $D(4,1)$ to form quadrilateral $ABCD$. .

1. What is the best name for quadrilateral $ABCD$? Justify your answer.

Explain why it is not a rhombus.

$ABCD$ is a parallelogram because opposite sides are parallel.

2. Determine $m∠DAB$ and $m∠BCD$. What is their relationship?

3. Write the equations of $\overleftrightarrow { A C }$ and $\overleftrightarrow { B D }$. Are the diagonals of $ABCD$ perpendicular?

Find the slope of each diagonal.

1. What are the coordinates of the intersection point of diagonals $\overleftrightarrow { A C }$ and $\overleftrightarrow { B D }$?

Use the eTool below to solve for each part of the problem.
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