Question 20
In the diagram below, $ABC$ is a right-angled triangle. Points $D,E$ lie on $AB$ while points $F,G$ lie on $BC$ such that $\triangle EFG$ and $\triangle DGC$ are right-angled isosceles triangles. It is given that $DC=3EG$ and the area of $\triangle DGC$ is $1$ cm$^2$. What is the area of $\triangle ADC$ in cm$^2$?
