This question was uploaded on 30/01/22 on social media accounts.
Solution:
ABC having half of the area of the square.
3, 6, 12 are assumed values and due to similar triangles, they must be in ratio 1:2:4.
ABF and EGF are similar triangles:
\[\color{green} {\frac{9}{12}=\frac{3}{9-x}}\]
\[\Rightarrow \color{green} {x=5}\]
Now, the Blue fraction is half of the ratio of Areas of triangles BDE and ABC:
\[\color{black} {\Rightarrow A_{Fraction}=\frac{\color{blue}{A(BDE)}}{2\times\color{red}{A(ABC)}}=\frac{\color{blue}{3\times5}}{2\times\color{red}{15\times15}}=\frac{1}{30}}\]
