The answer choices are in the photo

Answer:
15 feet
Step-by-step explanation:
The area (A) of a triangle is calculated as
A = [tex]\frac{1}{2}[/tex] bh ( b is the base and h the height )
Here A = 75 and h = 10, thus
75 = [tex]\frac{1}{2}[/tex] b × 10 = 5b ( divide both sides by 5 )
15 = b
That is the base of the sail is 15 feet