3 dotted horizontal and parallel lines are shown. Point Q is at the far left side of the top line, point R is at the far right of the second line, and point S is at the far left side of the bottom line. Lines are drawn from point Q to point R and from point R to point S. The angles formed are labeled, from top to bottom: 1, 2, 3, 4. Use the diagram to complete the statements.

The angle of depression from point R to point S is angle
.

The angle of elevation from point S to point R is angle
.

Angle 2 is the angle of elevation from
.

Angle 1 is the angle of