Well to find the area, you simply need to find the formulas! Sadly it specifically depends on the shape alothough that’s what googled for! Just look up the formulas and plug in the legnth width and height maybe even perimeter of base! There you have it!
Multiply each dimension by 35:-
17*35 = 595 cm
18*35 = 630 cm
19.7 * 35 = 689.5 cm
in meters the dimensions are L = 6.895 m, W = 6.3 m and H = 5.95 m