Respuesta :

Answer:

The surface area is 33ft².

Step-by-step explanation:

Sum the area of the square and of the four triangles.

[tex]

a = 3(3) + 4 ( \frac{3 ( 4)}{2} ) = \\ = 9 + 4( \frac{12}{2} ) = \\ = 9 + 2(12) = \\ = 9 + 24 = \\ = 33

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