A boy is standing at the top of the tower and another boy is at the ground at some distance from the foot of the tower, then the angle of elevation and depression between the boys when both look at each other will be

### Concept & Alternate Interior Angles Horizontal lines of sight drawn from an observer's eye are parallel to the ground. The line of sight connecting two observers acts as a transversal intersecting these parallel lines. $$ \text{Angle of Elevation} = \text{Angle of Depression} $$ ### Step-by-Step Solution 1. The boy at the top of the tower looks down, creating an angle of depression between his horizontal line of sight and the line connecting him to the boy on the ground. 2. The boy on the ground looks up, creating an angle of elevation between his horizontal line of sight (the ground) and the same connecting line. 3. Since both horizontal lines are parallel, the angles formed by the transversal line of sight are alternate interior angles. 4. By basic geometric properties, alternate interior angles between parallel lines are always equal. ### Exam Strategy & Shortcut This is a fundamental theoretical rule in trigonometry. Always remember that the angle of elevation from point A to point B is numerically identical to the angle of depression from point B to point A. No calculation is needed. ### Common Pitfall Assuming that the height of the tower makes the angle of depression larger because the observer is positioned "higher up" relative to the other. ### Final Answer Therefore, the correct answer is **Equal**.