Question: If the length of each side of an equilateral triangle is increased by 2 units, the area is found to be increased by $ 3+\sqrt{3} $ sq units. The length of each side of the triangle is
Options:
A) $ \sqrt{3}units $
B) $ 3\sqrt{3}units $
C) $ 3units $
D) $ 1+3\sqrt{3}units $
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Answer:
Correct Answer: A
Solution:
- Let the original side of equilateral triangle be x units
New length of each side $ =(x+2) $
According to the question,
$ \frac{\sqrt{3}}{4}{{(x+2)}^{2}}-\frac{\sqrt{3}}{4}(x^{2})=3+\sqrt{3} $
$ \Rightarrow $ $ \frac{\sqrt{3}}{4}[{{(x+2)}^{2}}-x^{2}]=3+\sqrt{3} $
$ \Rightarrow $ $ \frac{\sqrt{3}}{4}[4x+4]=3+\sqrt{3} $
$ \Rightarrow $ $ 4\sqrt{3}x+4\sqrt{3}=12+4\sqrt{3} $
$ \Rightarrow $ $ 4\sqrt{3}x=12 $
$ x=\frac{12}{4\sqrt{3}}=\sqrt{3} $