As megalodon is an ancestor of the great white they do have similar hunting styles but not the same. Studies show that megalodon attacked the tail or head of the whale. Demonstrated in this picture from the hawaii sighting video. This hunting style is also portrayed in shortfin mako sharks. Which attack turtles or large fish. The effectiveness of this strategy is shocking. First the shark slams into the whale with it's snout damaging the whale then the shark will propel itself forward in the window that the whale is incapacitated and attack the tale to let the prey bleed out and the whale can't escape.