Acathedral hull allows the boat to do what

It allows power boats to have stability while cruising. The cathedral hull  is like a trimaran in terehat it has one main  and two side hulls stuck together so that has a somewhat square to rectangular shape and therefore exhibits greater stability than a single hulled boat. It became more popular with the advent of fibreglass boats in the 1960's and '70s.

You should see a little paperclip on the bottom left corner you click on it and it gives you two options (camera and gallery)

Hypothesis: volumes of both figures are equal.the volume of  figure 1 is: .the volume of figure 2 is: .since , you can conclude that and . so, .volumes of figures are equal only when an angle in the basis is right (then figures will be the same), in another cases volume of figure 1 is less than volume of figure 2.the hypothesis was not correct in all cases.