Question

relating angles of elevation and depression
the angle of depression from point a to point b is __________ to the ____ of
elevation from point b to point a.

• the horizontal lines are parallel to each other because all horizontal lines are parallel to

the horizon and, therefore, parallel to ____________.

• alternate interior angles between two parallel lines are congruent by the alternate interior

angles theorem.

Explanation:

Step1: Analyze angle of depression and elevation

The angle of depression from A to B and the angle of elevation from B to A: since horizontal lines are parallel, by Alternate Interior Angles Theorem, these angles are congruent. So first blank: congruent, second blank: angle.

Step2: Analyze parallel horizontal lines

All horizontal lines are parallel to each other, so they are parallel to each other (or "one another"). So the blank: each other (or "one another").

Answer:

First blank: congruent; Second blank: angle; Last blank: each other (or "one another")