Actually Welcome to the Concept of the Polygons.
Since we can see, after assembling it becomes as prism like structure, so it's a
a.) Triangular Prism Polyhedron
b.) area of this Polyhedron is given as,
(area of triangle ×2)+(area of rectangle 1)+(area of rectangle 2)+(area of rectangle 3)
=> (1/2×8×6×2) + (6×5)+(8×5)+(10×5)
=> (48)+(30)+(40)+(50)
=>(48)+(120)
=>168 sq. units
Area = 168 sq. units