Question: 10. Find the length of the remaining side on each of the following right-angled triangles. Give your answers in surd form as simplified as possible.
$3cm$
$10\sqrt{2}cm$
$3\sqrt{3} cm$
$5\sqrt{3} cm$
1. **Problem 1:** Given a right-angled triangle with one leg $3cm$ and hypotenuse $10\sqrt{2}cm$, find the other leg.
2. **Formula:** Use the Pythagorean theorem: $$c^2 = a^2 + b^2$$ where $c$ is the hypotenuse, and $a$, $b$ are the legs.
3. **Step 1:** Let the unknown side be $x$. Then:
$$ (10\sqrt{2})^2 = 3^2 + x^2 $$
4. **Step 2:** Calculate squares:
$$ 100 \times 2 = 9 + x^2 $$
$$ 200 = 9 + x^2 $$
5. **Step 3:** Solve for $x^2$:
$$ x^2 = 200 - 9 = 191 $$
6. **Step 4:** Write $x$ in surd form:
$$ x = \sqrt{191} $$
7. **Simplification:** $191$ is prime, so $\sqrt{191}$ is already simplified.
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8. **Problem 2:** Given two sides $3\sqrt{3} cm$ and $5\sqrt{3} cm$ of a right triangle, find the remaining side.
9. **Step 1:** Identify which sides are legs or hypotenuse. Since $5\sqrt{3} > 3\sqrt{3}$, assume $5\sqrt{3}$ is hypotenuse.
10. **Step 2:** Let the unknown side be $y$. Apply Pythagorean theorem:
$$ (5\sqrt{3})^2 = (3\sqrt{3})^2 + y^2 $$
11. **Step 3:** Calculate squares:
$$ 25 \times 3 = 9 \times 3 + y^2 $$
$$ 75 = 27 + y^2 $$
12. **Step 4:** Solve for $y^2$:
$$ y^2 = 75 - 27 = 48 $$
13. **Step 5:** Simplify $y$:
$$ y = \sqrt{48} = \sqrt{16 \times 3} = 4\sqrt{3} $$
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**Final answers:**
- First triangle remaining side: $\sqrt{191} cm$
- Second triangle remaining side: $4\sqrt{3} cm$