# Perpendicular lines - Geometry and Coordinate Geometry

"How can you determine if two lines are perpendicular?"

This is what I understand out of it By definition, perpendicular lines intersect each other at 90 degree angle.

In co-ordinate geometry, product of their slopes is -1.

https://brainmass.com/math/trigonometry/perpendicular-lines-geometry-coordinate-geometry-176117

#### Solution Preview

In Geometry, we say two lines are perpendicular if they make an angle of 90 deg between themselves.

In Coordinate Geometry we learn that two lines are perpendicular if the product of their slopes is -1, right?

This means, there has to ...

#### Solution Summary

The concept of perpendicular lines illustrated clearly by connecting Geometry and Coordinate geometry.

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