In order to calculate the total surface area we just need to sum the area of the different faces.
From the picture we see that we have the following faces.
- 2 x A (two triangles)
- S (a rectangle)
- T (a rectangle)
- B (the base rectangle)
Now me calculate the area of each one:
[tex]A\text{ = }\frac{1}{2}\cdot12\cdot5\text{ = }30[/tex]
[tex]S\text{ = 5}\cdot5=\text{ 25}[/tex][tex]B=12\cdot5=60[/tex][tex]T=13\cdot5=65[/tex]
Now that we have the area of each face, we sum all the areas, taking in account the ones that appears twice:
[tex]\text{Total area = 2}\cdot A+S+T+B=2\cdot30+25+60+65=210[/tex]
And, because the lenghts are measured in ft, the final answer is:
[tex]\text{Total area = 210 ft}^2[/tex]
Note:
[tex]\text{Area of a triangle = }\frac{1}{2}\cdot\text{base}\cdot\text{height}[/tex][tex]\text{Area of a rectangle = base }\cdot\text{ height}[/tex]
