This is a clear example of the Pythagorean Theorem, a relation of all sides in a right triangle. The equation itself is a^2 + b^2 = c^2. By simply plugging in the given values into the triangle, you would get the answer.
Step-by-step explanation: Since the club split the pies into 5 pieces and then had a total of 45 slices, you would first divide 45 by 5 and you would get 9. The question stated that the cafeteria gave 2 pies and they are asking how much the club made. So you would subtract 9 by 2 to get 7. This concludes to that the club made 7 pies in total. Hope that helps!