Answer:
perpendicular
Explanation:
To determine if AB and CD are parallel, perpendicular, or neither, we need to get the slope of AB and CD first
Given A (−1, 3), B (0, 5),
Slope Mab = 5-3/0-(-1)
Mab = 2/1
Mab = 2
Slope of AB is 2
Given C (2, 1), D (6, −1)
Slope Mcd = -1-1/6-2
Mcd = -2/4
Mcd = -1/2
Slope of CD is -1/2
Take their product
Mab * Mcd = 2 * -1/2
Mab * Mcd = -1
Since the product of their slope is -1, hence AB and CD are perpendicular