It is to be noted that the total surface area of the three-dimensional shape is 71 units²
First we compute the surface area of the triangles:
Surface area of the triangle = (b x h)/2
Where b = base
h = height
Note that there are two similar triangles so total surface area of the triangular sides will be:
(b x h)/2 x 2
b x h
= 4 x 1.5
= 6
When spread out the way it is given, the total length of the quadrilateral sides is 13 units and the breadth is 5
total surface area of this =
13 x 5 = 65 units
Thus the total surface area of the entire shape is
65 units + 6 units
= 71 units²