Answer: First option is correct.
Step-by-step explanation:
Since we have given that
Dimensions of lower most rectangle is 4 meters long and 5 meters wide.
So, Area of 2 lower and upper rectangle is
[tex]2\times Length\times breadth\\\\=2\times 4\times 5\\\\=40\ sq.\ units[/tex]
Dimensions of middle rectangle is 6 units and 4 meters long.
Area of middle rectangle is given by
[tex]Length\times breadth\\\\=4\times 6\\\\=24\ sq.\ units[/tex]
Dimensions of triangle are as follows:
Height = 4 units and base = 6 units.
So, Area of 2 triangles would be
[tex]2\times \dfrac{1}{2}\times 6\times 4\\\\=24\ sq.\ units[/tex]
So, Total surface area of the triangular prism is given by
40+24+24
=40+48
=84 sq. units
Hence, First option is correct.
