Line of sight

1. Mark the observer's eye. 2. Mark the target object point. 3. Join them with a straight slant line. 4. Label that line as the line of sight. 5. Use it with the horizontal to form the angle.

Draw a straight slant segment from the observer's eye to the top or target point of the object. Label it clearly as line of sight.

A common wrong answer is to treat the ground distance as the line of sight. The ground distance is only the adjacent side, not the viewing line.

The line of sight is the straight line joining the observer's eye to the object being seen.

The line of sight is the straight line joining the observer's eye to the object being seen. Line of sight is the straight slant line from eye to object; it helps create the right triangle for trigonometric ratios. If a student at ground level sees the top of a lamp post, the straight line from the eye to the lamp post top is the line of sight.

In trigonometry problems, the line of sight is the slant line that connects the observer and the target object. It is the key line used to form the angle of elevation or depression. Without this line, we cannot build the right triangle needed for height and distance questions. The line of sight is always straight, not curved, because we imagine the shortest viewing path. Line of sight is the straight slant line from eye to object; it helps create the right triangle for trigonometric ratios. A person standing on the ground sees the top of a tree. The straight segment from the eye to the top of the tree is the line of sight, and together with the horizontal and vertical it forms a right triangle. Questions ask you to identify the line of sight in a diagram, or to use it indirectly when forming a trigonometric ratio. A common wrong answer is to treat the ground distance as the line of sight. The ground distance is only the adjacent side, not the viewing line.