Question

What is the relationship between two perpendicular lines? What are some examples?

Answer 1

All four angles formed by two perpendicular lines are measured `90^o`.

Explanation:

By definition, perpendicular lines are those that intersect at right angle.

The definition requires only one angle (out of four formed by two intersecting lines) to be the right angle (that is, measure at `90^o`). Obviously, all others are also measure `90^o` since an angle adjacent to one measured `90^o` must complement it to a straight angle of `180^o` and, hence, must be `90^o` itself.

Example of perpendicular lines: