Answer:
b = 45 ft
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
b² + 60² = 75²
b² + 3600 = 5625 ( subtract 3600 from both sides )
b² = 2025 ( take the square root of both sides )
b = [tex]\sqrt{2025}[/tex] = 45
