Chapter 2 Linear Equations and Functions - 2.2 Find Slope and Rate of Change - 2.2 Exercises - Skill Practice - Page 86: 18

perpendicular

By using the slope formula, the slopes of the lines are: $m_1=\frac{y_2-y_1}{x_2-x_1}=\frac{-1-(-4)}{3-6}=\frac{3}{-3}=-1.$ $m_2=\frac{y_2-y_1}{x_2-x_1}=\frac{5-7}{-4-(-2)}=\frac{-2}{-2}=1.$ Since $m_1m_2=-1$, they are perpendicular.