Find the angle of elevation of the sun's altitude when the height of shadow of a vertical pole is equal to its height.
(a) 30°    (b) 60°    (c) 45°    (d) 90°
In Fig. 9.74, what are the angles of depressions of the top and bottom of a pole from the top of a tower h m high.
(a) 45°, 70°    (b) 45°, 60°    (c) 45°, 30°    (d) 45°, 45°
The angle of elevation of the top of a tower from a point on the grounds which is 30 m away from the foot of the tower is 30°. The height of the tower is
(a)  10 m      (b)        (c)     (d)  30 m
A ladder leaning against a wall makes an angle of 60° with the horizontal. If the foot of the ladder is 2.5 m away from the wall, find the length of the ladder.