### Home > CC4 > Chapter 7 > Lesson 7.1.7 > Problem 7-80

7-80.

On graph paper, plot the points *A*(–5, 7) and *B*(3, 1). *7-80 HW eTool** *(Desmos) Homework Help ✎

Calculate

*AB*(the length of*AB*).Locate the midpoint of

*AB*and label it point*C*. What are the coordinates of point*C*?Calculate

*AC*. Can you do this without using the Pythagorean Theorem?

Use the Pythagorean Theorem to find the length of *AB*.

Use two congruent slope triangles to find the midpoint.

Because *C* is the midpoint, what does that tell you about the length of *AC*?

Use the hints in the eTool below for parts (a-c).

Click on the link at right for the full eTool version: INT1 7-80 HW eTool