Could someone help me to solve this pls!

Answer:
15 ft²
Step-by-step explanation:
The volume of a cone is given in terms of the base area (B) and height (h) by the formula ...
... V = (1/3)Bh
Putting in the given numbers, you have ...
... 35 ft³ = (1/3)B(7 ft)
... B = (35·3/7) ft² = 15 ft² . . . . . . solve for B