Given:
a = x ft
b = 40ft
c = 65ft
According to the Pythagorean Theorem, we can find the value of the hypotenuse of a right triangle through the following formula:

![c=\sqrt[]{a^2+b^2}](https://img.qammunity.org/2023/formulas/mathematics/college/6uwqakmkjq6nua21bpopztkrf20jt2flji.png)
Given that:
a = side
b = side
c = hypotenuse
With this formula, we can manipulate it ti find the value of a side instead.


![a=\sqrt[]{c^2-b^2}](https://img.qammunity.org/2023/formulas/mathematics/college/w8a659hy9dfa00h8fbbcv9n4x963kxnsvi.png)
Next, we plug in the given values that we have
![a=\sqrt[]{c^2-b^2}](https://img.qammunity.org/2023/formulas/mathematics/college/w8a659hy9dfa00h8fbbcv9n4x963kxnsvi.png)
![x=\sqrt[]{(65)^2-(40)^2}](https://img.qammunity.org/2023/formulas/mathematics/college/u146cag7wt2rmx88fkz25nm8uv5wb05sgr.png)
![=\sqrt[]{4225-1600}](https://img.qammunity.org/2023/formulas/mathematics/college/ot3e7yxlkj1dc2ar87i2974vt7pq2f6l7g.png)
![=\sqrt[]{2625}](https://img.qammunity.org/2023/formulas/mathematics/college/1h4c6u6g1v591q0j0jdqd5u3xzic9g7veb.png)

Since the question are asking to round the answer to the nearest tenth, the final answer would be
