Answer:
84.9m²
Step-by-step explanation:
Surface area Formula
[tex]SA = A + \frac{3}{2} bh[/tex]
A is the area if the base, b is the length of the base on one of the faces and h is the height of one of the faces.
[tex]a = 6.9[/tex]
[tex]b = 4[/tex]
[tex]h = 13[/tex]
Formula
[tex]SA = 6.9 + \frac{3}{2} (4 \times 13[/tex]
[tex]SA = 6.9 + \frac{3}{2} (52)[/tex]
[tex]SA = 6.9 + 78[/tex]
[tex]SA = 84.9[/tex]
The surface area is 84.9m²
