Match the following.
i)horizontal a)is the angle between line of sight and the horizontal levellevel when the object is above the horizontal line.ii)line of sightb)is the line running parallel to the plane on which the object is kept.iii)angle of c)is the line drawn from the eye of the observer to the elevationpoint in the object viewed by the observer.iv)angle ofd)is the angle between line of sight and the horizontal depressionlevel when the object is below the horizontal line.