Angle of elevation of the top of an incomplete tower from a point at a distance 50 m from its foot is 30°. How much should the height of the tower be increased so that the angle of elevation of the top will be 45° from that point?
WBBSE
Class X
Mathematics
Application of Trigonometric Ratios
5
2023
In ΔABO
tan 30° = \text{AB}\over \text{OA}
or, 1\over √3 = \text{AB}\over 50
or, AB = 50\over √3 = 28.86 m
In ΔAOC,
tan 45° = \text{AC}\over \text{OA}
or, AC = 50 m
Height of the of tower increased = 50 m – 28.86 m
= 21.13 m
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