In order to check whether the length of the sides are applicable to form a triangle is that we have to make sure that the sum of the length of two side should be greater than the third side.
18.5 m, 36.9 m, and 16.9 m
18.5 m < 36.9 m +16.9 m
36.9 m < 18.5 m +16.9 m
16.9 m < 18.5 m + 36.9 m
So the dimensions are correct!