What is the formula for finding the weight of a 3d trapazoid? 1x1x1=.283lb

Question

In trying to find the weight of a trapazoid made out of metal to be specific I need to make this trapazoid +-170 lb.  6 inches tall 15 inches at the base and 6 inches deep with 45 degree sides 

Answer 1

The mass is going to depend on the density (ρ) of the material.

 

The volume times the density will give you mass V * ρ = m