Calculate the area of each face that is covered by the paint:
Area of 1 and 4:
Use Pythagorean theorem to find 1/2 b:
![\begin{gathered} (1)/(2)b=\sqrt[]{(5\operatorname{cm})^2-(4\operatorname{cm})^2} \\ \\ (1)/(2)b=\sqrt[]{25\operatorname{cm}^2+16cm^2} \\ \\ (1)/(2)b=\sqrt[]{41cm^2} \\ \\ b=2\sqrt[]{41}cm \\ \\ \\ A_1=A_4=(1)/(2)b\cdot h \\ \\ A_1=A_4=(1)/(2)(2\sqrt[]{41}cm)(4\operatorname{cm}) \\ \\ A_1=A_4=4\sqrt[]{41}cm^2 \end{gathered}]()
Area of 2 and 3:
![\begin{gathered} A_2=A_3=w\cdot l \\ \\ A_2=A_3=5\operatorname{cm}\cdot9\operatorname{cm} \\ \\ A_2=A_3=45cm^2 \end{gathered}]()
Area of 5 and 7:
![\begin{gathered} A_5=A_7=w\cdot l \\ \\ \\ A_5=A_7=6\operatorname{cm}\cdot7\operatorname{cm} \\ \\ A_5=A_7=42\operatorname{cm} \end{gathered}]()
Area of 6 and 8:
![\begin{gathered} A_6=A_8=w\cdot l \\ \\ A_6=A_8=9\operatorname{cm}\cdot7\operatorname{cm} \\ \\ A_6=A_8=63\operatorname{cm}^2 \end{gathered}]()
Then, the total area cover by the paint is:
![\begin{gathered} A_T=A_1+A_2+A_3+A_4+A_5+A_6+A_7+A_8_{} \\ \\ A_T=(4\sqrt[]{41}+45+45+4\sqrt[]{41}+42+63+42+63)cm^2 \\ \\ A_T=(300+8\sqrt[]{41})cm^2 \\ \\ A_T\approx351.2\operatorname{cm}^2 \end{gathered}]()
If the paint can cover 1000 square centimeters the percentage used to cover the entire house is: 35.12%
![351.2\operatorname{cm}\cdot\frac{100}{1000\operatorname{cm}^2}=35.12]()