1/10 of an ounce is the answer
We have the area of the base of a triangular prism= a*b
the volume of triangular prism =a*b*c( where c is the height) so that 210=a*b*14 ==> 210= base area*14==> base area= 210/14
11.4 should be the answer
if you mean tens then it is 10
