Lil decides to estimate the height of the Empire State Building. She measures the angle θ of elevation of the spire atop the building as 19°. After walking x = 9.10 ✕ 102 ft closer to the building, she finds the angle to be 23.8°. Use Lil's data to estimate the height h of the Empire State Building.

2 answers

Draw a diagram.
Review the definition of the cotangent.

If the height is h, then

h cot19° - h cot23.8° = 910
1st measure __ h / tan(19º) = d

2nd measure
__ h / tan(28.3º) = d - 910

substitute for d and solve for h