Question

what defines perpendicular lines?
a. lines that share a common endpoint
b. lines that run parallel to each other
c. lines that intersect at a 90° angle
d. lines that divide a plane into three equal parts

Explanation:

Perpendicular lines are defined by their intersection at a right angle ($90^{\circ}$).

• Option a describes lines with a common endpoint (not necessarily perpendicular).
• Option b refers to parallel lines (which never intersect).
• Option d has no relation to the definition of perpendicular lines.

Answer:

C. Lines that intersect at a \(90^{\circ}\) angle