Answer:
89.9 feets
Step-by-step explanation:
The diagrammatic representation of the problem is attached below.
The height, h of the tree can be calculated using the trigonometric relation :
Cosθ = adjacent / hypotenus
Cos 42 = h / 121
0.7431448 = h / 121
Height, h of tree = 121 * 0.7431448
Height = 89.9 feets