Answer:
Option C. 3
Explanation:
Let M1 be the slope of the red line
Let M2 be the slope of the green line
From the question:
Slope of red line (M1) = – 1/3
Slope of green line (M2) =.?
The slopes of perpendicular lines are related as follow:
M1 = –1 / M2
With the above formula, the slope of the green line (M2) can be obtained as illustrated below:
Slope of red line (M1) = – 1/3
Slope of green line (M2) =.?
M1 = –1 / M2
– 1/3 = –1 / M2
Cross multiply
– 1 × M2 = – 1 × 3
– 1 × M2 = – 3
Divide both side by –1
M2 = – 3/ –1
M2= 3
Therefore, the slope of the green line is 3.