show that AB // DC,A=(0,2),B=(4,-1),C=(1,-5),D=(-3,-2)?
slope AB = (-1-2)/(4-0) = -3/4
slope CD = (-2+5)/(-3-1) = 3/-4 = -3/4
What have you learned about lines that have the same slope ?
slope CD = (-2+5)/(-3-1) = 3/-4 = -3/4
What have you learned about lines that have the same slope ?