Algebra-1

Question Analysis
This question tests the student's understanding of the fundamental property of perpendicular lines. The student must recognize that the product of the slopes of two perpendicular lines is $$ -1 $$.

Key Concept Explanation
Perpendicular lines intersect at a right angle (90 degrees), and the product of their slopes is $$ -1 $$: $$ m_1 \cdot m_2 = -1 $$. This is a key property that distinguishes perpendicular lines from other types of lines.

Step-by-step Solution
1. Recall the definition of perpendicular lines: they intersect at a right angle.
2. The product of the slopes of two perpendicular lines is...