If the area of an equilateral triangle is $24\sqrt{3}$ sq. cm, then its perimeter is
Aptitude
Area
Difficulty: Easy
Choose an option
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A$2\sqrt{6}$ cm
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B$4\sqrt{6}$ cm
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C$12\sqrt{6}$ cm
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D96 cm
Answer
Correct Answer: $12\sqrt{6}$ cm
Explanation
### Concept & Formula
For an equilateral triangle of side $a$:
Area $$ A = \frac{\sqrt{3}}{4}a^2 $$
Perimeter $$ P = 3a $$
### Step-by-Step Solution
1. Given Area $= 24\sqrt{3}$.
2. $\frac{\sqrt{3}}{4}a^2 = 24\sqrt{3}$.
3. Divide both sides by $\sqrt{3}$: $\frac{a^2}{4} = 24$.
4. $a^2 = 96 \Rightarrow a = \sqrt{96} = \sqrt{16 \times 6} = 4\sqrt{6} \text{ cm}$.
5. Perimeter $= 3a = 3(4\sqrt{6}) = 12\sqrt{6} \text{ cm}$.
### Exam Strategy & Shortcut
Write $24\sqrt{3}$ as $\frac{\sqrt{3}}{4} \times (96)$. The side squared is 96, so the side is $\sqrt{96}$. Multiply by 3 for perimeter: $3\sqrt{96} = 3 \times 4\sqrt{6} = 12\sqrt{6}$.
### Common Pitfall
Forgetting to take the square root of 96, or calculating the perimeter as just $4\sqrt{6}$ (which is the side, not the perimeter).
### Final Answer
Therefore, the correct answer is **$12\sqrt{6}$ cm**.