Question

What must be true about the slopes of two perpendicular lines, neither of which is vertical?

The slopes are equal.
The product of the slopes is –1.
One of the slopes must equal 0.
The product of the slopes is 1.

Answer 1

The product of the slopes is –1

Answer 2

In a plane, line b is perpendicular to line f, line f is perpendicular to line g, and line h is parallel to line f. Which of the following must be true?

hg
g || f
b || h
fh

Answer 3

In a plane, line b is perpendicular to line f, line f is perpendicular to line g, and line h is parallel to line f. Which of the following must be true?

hg
g || f
b || h
fh