A circle is inscribed is an equilateral triangle. If the in-radius is 21 cm, what is the area of the triangle?

(b): Centre of the circle lies on the median. If ?a? is side of equilateral $\Delta \le$, median $=$a$3$√$2$       In - radius $=$a$3$√$2$×$1$3$=$1$2$3$\surd$a$a=21$ $\Rightarrow$a=42$3$√$Nowf\in darea$=$3$√$4$a$2$