The measure of side b as 64 ft is incorrect. The accurate measure would be 8 ft.
According to the Pythagorean theorem, the square of the hypotenuse of a right-angle triangle is the sum of squares of the opposite and the adjacent sides. Mathematically:
In this case, the hypotenuse = 10 ft, the opposite = 6 ft and the adjacent = b
Hence,
b^2 = 10^2 - 6^2
= 100 - 36
= 64
b = √64
= 8 ft
Thus, the side b is 8 ft and not 64 ft.
More on the Pythagorean theorem can be found here: brainly.com/question/16426393