To find the length of a leg of a right triangle using the Pythagorean theorem, we can use the formula:
\[ a^2 + b^2 = c^2 \]
where:
- \( c \) is the length of the hypotenuse,
- \( a \) and \( b \) are the lengths of the legs.
In this case, we know:
- One leg \( a = 8 \) feet,
- The hypotenuse \( c = 10 \) feet,
- We need to find the other leg \( b \).
Plugging the known values into the formula:
\[ 8^2 + b^2 = 10^2 \]
Calculating the squares:
\[ 64 + b^2 = 100 \]
Now, isolate \( b^2 \):
\[ b^2 = 100 - 64 \]
\[ b^2 = 36 \]
Now take the square root of both sides to find \( b \):
\[ b = \sqrt{36} \]
\[ b = 6 \text{ feet} \]
So the length of the other leg of the triangle is 6 feet.
Therefore, the correct answer is:
D) 6 ft.