Answer:
422.44 feet
Step-by-step explanation:
Let A, B, X, and H represent the left-most observation point, the observation point to its right, the point immediately below the apex, and the height of the apex, respectively.
Then the definition of the cotangent function tells us ...
AX = H·cot(42°)
BX = H·cot(48.85°)
Since the figure tells us AB = 100 feet, we have ...
AB = AX -BX
100 = H·cot(42°) -H·cot(48.85°)
H = 100/(cot(42°) - cot(48.85°)) ≈ 422.44 . . . . ft
The current height of the pyramid is 422.44 feet.
