Question

Use slope to determine if lines AB and CD are parallel, perpendicular, or neither I5. A(-3, 13), B(4, -15). C(-2.5). D(1.-7)mn(AB)m CDTypes of Lines

Answer 1

If two lines are parallel they have the same slope, but if they are perpendicular the slope is the negative reciprocal of the original line.

To calculate the slope:

$\begin{gathered} m=\frac{y_2-y_1}{x_2-x_1} \\ m_{AB}=\frac{-15-13}{4-(-3)} \\ m_{AB}=\frac{-28}{7}=-4 \end{gathered}$$\begin{gathered} m_{CD}=\frac{-7-5}{1-(-2)}_{} \\ m_{CD}=\frac{-12}{3}=-4 \end{gathered}$

Their slope are the same, so the lines would be parallels.