<PRE><B>Question 1115354</B>
Amirah stands at a point B due east of a vertical tower OT and observes that the angle of elevation of the top of the tower is 40 Deg. She walks 70m due north and finds that the angle of elevation of T from her new position at C is 25 deg. Find the height of the tower and hence distance OB.
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Sketch the picture of the two observation triangles and the ground triangle
You have three right triangles.
1st:: base = OB ; height = OT; base angle = 40 degrees
OT = OB*tan(40 deg) 
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2nd:: base = CO ; height = OT ; base angle = 25 degrees
OT = OC*tan(25 deg)
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3rd:: base = OB ; height = 70 ; OC = sqrt(OB^2+70^2) ft
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Cheers,
Stan H.
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