Question

Line m is perpendicular to line n. Which statement about lines m and n is true?

Answer 1

see below

Explanation:

Slopes of perpendicular lines are negative reciprocals of each other:

m1 = -1/m2

(m1)(m2) = -1

So, their product is -1.

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Additional comment

The rule above does not apply to horizontal and vertical lines, because the slope of a vertical line is undefined. In this problem, that is not an issue, because the lines are not aligned with the axes.