Chapter 8 - Right Triangles and Trigonometry - 8-4 Angles of Elevation and Depression - Practice and Problem-Solving Exercises - Page 519: 13

$\angle 5$ is at an angle of elevation from the horizontal line of Max's eye to the level of the waterfall.

$\angle 5$ is at an angle of elevation from the horizontal line of Max's eye to the level of the waterfall. The angle is at an incline from Max to the waterfall.