Y = - 3x + 6 and y = 1/3 x - 8

Determine if the angles are perpendicular, parallel, or neither

If the angles are perpendicular, the slopes are the negative reciprocal of each other.

If the angles are parallel, the slopes are the same as each other.

If the slopes are neither the same as each other or the negative reciprocal of each other, then the angle is neither parallel or perpendicular.

Looking at the y = - 3x + 6 equation, the negative reciprocal of the slope, - 3, is 1/3. Looking at the y = 1/3x - 8 equation, the negative reciprocal of the slope is - 3.

Since the slopes are negative reciprocals of each other the angles are perpendicular.

those are perpendicular angles because the only thing that changes is the x part.