Exploring with Volume and water Depth

We are determining which option is the best for removing water from a bucket.  Option 1: 3 scoops from a small cup.  Option 2: 1 scoop from a large cup.  The catch is that no water could be used to help determine the answer.  We measured with string, and rulers, and calculated using formulae.  The cups were not cylinders, so that meant we needed to make some decisions about how to model the cups.     
    
   
Once we chose the cups to use, we scooped water out of a big bucket and watched the height drop.  This showed a linear relation, which we then found equations for.