In the given figure, AB is an equilateral triangle. Two circle of radius 6 cm and 18 cm are inscribed in the triangle. What is the side of an equilateral triangle (in cm)?
Answer & explanation
Correct answer: option 4
Big circle touches all the side of triangle, it means it is in-circle of equilateral triangle.
So, inradius of equilateral triangle = \(\frac{a}{2\sqrt {3}}\)
⇒ \(\frac{a}{2\sqrt {3}}\) = 18
⇒ a = \({36\sqrt {3}}\)