Question

two lines intersecting at a right angle
form a line
are parallel.
are perpendicular.
form a ray

Explanation:

Step1: Analyze each option

• Option A: Two lines intersecting at a right - angle do not form a line. A line is a straight one - dimensional figure.
• Option B: Parallel lines do not intersect.
• Option C: By the definition of perpendicular lines, two lines that intersect at a right angle (\(90^{\circ}\)) are perpendicular.
• Option D: A ray has one endpoint and extends infinitely in one direction. Two intersecting lines (even at a right angle) do not form a ray.

Answer:

C. are perpendicular