### Home > A2C > Chapter 12 > Lesson 12.1.1 > Problem12-22

12-22.

Given the points $A (3, 2)$ and $B (-21, 0),$ determine each of the following.

1. The slope of the line $\overleftrightarrow{AB}$.

$\frac{(0) - (2)}{(-21) - (3)}$

$\frac{1}{12}$

1. The length of $\overline { A B }$.

$\sqrt{(-21-3)^2+(0-2)^2}$

$\sqrt{580}$

1. The midpoint of $\overline { A B }$.

Take the average of the $x$-values, and of the $y$-values.

1. An equation of $\overleftrightarrow{AB}$.

Use the slope you found in part (a) to find the y-intercept and write an equation.