To find the area,we can use Heron’s formula:

*Heron’s formula is a formula that use the 3 sides of triangle to find the area.
In this case:
s=30/2
s=15
The length of the triangle:
30÷3
=10ft
The area:
=_/15(10-15)(10-15)(10-15)
=_/15(5)(5)(5)
=_/1875
=43
=25_/3 sq.ft
Therefore the answer is B.
Hope it helps!