Help me with this please

Answer:
Step-by-step explanation:
The diagonal gives you a 30°-60°-90° triangle. The lengths of the sides of a 30°-60°-90° triangle are in the ratio 1:√3:2.
The side opposite the 60° angle is 12 ft.
The side opposite the 30° angle is 12/√3 ft
The side opposite the 90° angle is 2×12/√3 = 24/√3 = 24√3/3 = 8√3 ft