1. **State the problem:** We are given a right triangle where the hypotenuse is 225 and one leg is 7. We need to find the length of the other leg. 2. **Formula used:** In a right triangle, the Pythagorean theorem applies: $$a^2 + b^2 = c^2$$ where $c$ is the hypotenuse and $a$, $b$ are the legs. 3. **Identify known values:** Here, $c = 225$ and one leg, say $a = 7$. We want to find $b$. 4. **Apply the formula:** $$7^2 + b^2 = 225^2$$ 5. **Calculate squares:** $$49 + b^2 = 50625$$ 6. **Isolate $b^2$:** $$b^2 = 50625 - 49$$ $$b^2 = 50576$$ 7. **Find $b$ by taking the square root:** $$b = \sqrt{50576}$$ 8. **Calculate the square root:** $$b = 224.9$$ (approximately) **Final answer:** The missing side is approximately $224.9$ units long.