Find an expression for the total area of the figure expressed by x. 

The circumference of the whole figure is 
\[4x+4y+4x=12   \Rightarrow   8x+4y=12\]
dividing both sides by $4$ we get
\[(1)       2x+y=3. \]
Hence $y=3-2x$.

The total area of the figure is
\[A=x^2+x^2+y^2=2x^2+y^2.\]
Substituting $y=3-2x$ we get
\[A=2x^2+(3-2x)^2\]
which is an expression for the area in terms of $x$.