When the line of sight is above the horizontal level the angle formed is ____.

The ___ is an angle formed by the line of sight with the horizontal when the point is below the horizontal level.

Write the use of horizontal line test.

During a projectile motion if the maximum height equals the horizontal range,then the angle of projection with the horizontal is :

A man observes that when he moves up a distance c metres on a slope, the angle of depression of a point on the horizontal plane from the base of the slope is 30^0, and when he moves up further a distance c metres, the angle of depression of that point is 45^0dot The angle of inclination of the slope with the horizontal is.

Water level is maintained ina cylindrical vessel up to a fixed height H. The vessel is kept on a horizontal plane. At what height above the bottom should a hole be made in the vessel so that the water stream coming out of the hole strikes the horizontal plane at the greatest distance from the vessel.

A man is standing on the deck of a ship, which is 40m above water level. He observes the angle of elevation of the top of a hill as 60^(@) and the angle depression of the base of the hill as 30^(@) . Calculate the distance of the hill from the ship and the height of the hill, (sqrt(3)=1.732) .

A ramp for unloading a moving truck, has an angle of elevation of 30^(@) . If the top of the ramp is 0.9m above the ground level, then find the length of the ramp.