Question

The area of an equilateral \( \Delta ABC \) is \( 169\sqrt{3} \text{ cm}^2 \).  

Find the in-radius of \( \Delta ABC \).

• A. $10/\sqrt{3}$
• B. $13/\sqrt{3}$
• C. $12/\sqrt{3}$
• D. $11/\sqrt{3}$

Hint:

In an equilateral triangle, the circum-radius ($R$) is exactly double the in-radius ($r$). So, $R = a/\sqrt{3}$ and $r = a/2\sqrt{3}$.

Answer 1

The Correct Option is B