Answer:
44.73 m
Step-by-step explanation:
Given that the angle of elevation of an unfinished tower from a point of 120m away from its base is 25 degrees.
Using trigonometry ratio, the height of the tower can be calculated by
Tan Ø = height / base
Tan 25 = height / 120
Make height the subject of formula
Height = 120 × tan 25
Height = 55.96 m
How much higher will the tower need to be raised so that its angle of elevation from the same point will be 40 degrees?
Using the same formula to calculate the new height.
Tan 40 = new height / base
Tan 40 = new height / 120
Make the new height the subject of the formula.
New height = 120 × tan 40
New height = 100.69 m
Increase in height = new height - height
Increase in height = 100.69 - 55.96
Increase in height = 44.73m
Therefore, the tower will need 44.73m to be raised so that its angle of elevation from the same point will be 40 degrees.
. Then you would cross multiply which would result in: 
. Divide by 9 on both sides and 
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