(b) 2 : 4 : 3.
For an equilateral triangle of side a units,
In-radius = \(\frac{a}{2\sqrt3}\) units
⇒ Diameter of inscribed circle = \(\frac{a}{\sqrt3}\) units
Circumradius = \(\frac{a}{\sqrt3}\)
⇒ Diameter of circumscrible circle = \(\frac{2a}{\sqrt3}\) units
Height = \(\frac{\sqrt3}{2}a\) units.
∴ Required ratio = \(\frac{a}{\sqrt3}\) : \(\frac{2a}{\sqrt3}\): \(\frac{\sqrt3}{2}a\) = 2a : 4a : 3a = 2 : 4 : 3.