Answer: 304.56 square meters
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Work Shown:
area of triangle = (1/2)*base*height
area of triangle = (1/2)*7.2*4.8
area of triangle = 17.28
There are two of these triangles, so the surface area of all the triangles combined is 2*17.28 = 34.56
Now let's calculate the lateral surface area (LSA)
LSA = (perimeter of triangular base)*(depth of prism)
LSA = (7.2+4.8+6)*(15)
LSA = (18)*(15)
LSA = 270
Add this onto the previous area of the triangles
total surface area = (base area)+(LSA) = 34.56+270 = 304.56