Answer :
In order to determine the area tota that Sina needs to paint, first, calculate the area of both walls
[tex]\begin{gathered} \text{Wall}_1=2.7\cdot4 \\ \text{Wall}_1=10.8m^2 \\ \text{Wall}_2=2.7\cdot3 \\ \text{Wall}_2=8.1m^2 \end{gathered}[/tex]then, calculate the area of the door
[tex]\begin{gathered} \text{Door}=1\cdot2.3 \\ \text{Door}=2.3m^2 \end{gathered}[/tex]Finally, add the area of both walls and subtract the area of the door
[tex]\begin{gathered} 10.8+8.1-2.3 \\ 16.6m^2 \end{gathered}[/tex]Sina needs to paint 16.6 square meters.