To find out how high the ladder will reach using the Pythagorean Theorem, you can use the formula:
\[ a^2 + b^2 = c^2 \]
where:
- \( a \) is the height the ladder reaches,
- \( b \) is the distance from the base of the house to the bottom of the ladder (6 ft), and
- \( c \) is the length of the ladder (12 ft).
Plugging in the values: \[ a^2 + 6^2 = 12^2 \]
This simplifies to: \[ a^2 + 36 = 144 \]
Next, subtract 36 from both sides: \[ a^2 = 144 - 36 \] \[ a^2 = 108 \]
Now, take the square root of both sides to find \( a \): \[ a = \sqrt{108} \approx 10.39 \]
Rounding to the nearest tenth, \( a \approx 10.4 \) ft.
So, the correct answer is 10.4 ft.