The surface of the prism consists of the sum of 5 surfaces. Two equal triangles and three rectangles.
The area of the two triangles is: 2(4*6/2)=24 m^2
The area of the 1st rectangle: 6*22=132 m^2
The area of the 2nd rectangle: 7.21*22=158.62 m^2
The area of the 3rd rectangle: 4*22=88 m^2
The sum equals: 402.62 m^2
