Surface area is just the area of all these 4 triangles plus the rectangle.
First we can find the area of the rectangle.
[tex]\sf A=lw[/tex]
Half of the length is 28 cm, so the full length must be 28 * 2 = 56 cm.
[tex]\sf A=(56)(27)[/tex]
[tex]\sf A=1512cm^2[/tex]
The base for the left and right triangles are 27. The heights would be the net length minus half the length of the rectangle:
[tex]\sf 82.8-28=54.8\? cm[/tex]
Calculate the area:
[tex]\sf A=\dfrac{1}{2}bh[/tex]
[tex]\sf A=\dfrac{1}{2}(27)(54.8)[/tex]
[tex]\sf A=739.8\?cm^2[/tex]
We have two of these triangles.
[tex]\sf 739.8\times 2=1479.6\? cm^2[/tex]
Now do the other two pair of triangles. The bases for them are 28 + 28 = 56 cm. The heights would be the net width minus the width of the rectangle:
[tex]\sf 81.2-27=54.2\?cm[/tex]
Now find the area:
[tex]\sf A=\dfrac{1}{2}bh[/tex]
[tex]\sf A=\dfrac{1}{2}(56)(54.2)[/tex]
[tex]\sf A=1517.6\? cm^2[/tex]
We have two of these triangles.
[tex]\sf 1517.6\times 2=3035.2\?cm^2[/tex]
Add all the areas together:
[tex]\sf 1512+1479.6+3035.2=\boxed{\sf 6026.80\? cm^2}[/tex]