Answer:
A. 4
Explanation:
Perpendicular lines have special slopes.
Perpendicular Lines
Perpendicular lines are lines that intersect at a 90° angle. When two lines intersect, they form 4 angles. In the case of perpendicular lines, all four angles have a measurement of 90°. We can tell that the red and green lines are perpendicular because they form perfect right angles. Remember that a right angle is an angle with a measurement of 90°.
Perpendicular Slopes
We could find the slope of the red line through the slope formula, but we do not need to. All perpendicular lines have correlated slopes. The slope of a perpendicular line will be the negative reciprocal. This means to find the slope we need to flip the sign of the slope and flip the numerator and denominator. Since the green line has a slope of -1/4, the slope of the red line must be 4.