Using the method that CalculatorUser said, you split the triangle into two 30-60-90 triangles. We get that the height of the isosceles triangle is simply just 2, and the base is 4sqrt3. Using the formula for triangle area, we get that the area of the triangle 4sqrt3.
(That calculus method looks hard!)
First, we want to find the volume of the barrel. The formula for the volume of a cylinder is h* π * r^2. Substituting 15 in for h and 10 in for r, we get that the volume of the barrel is 1500π. Now, we must find the area fo the bucket. The formula for the volume of a hermisphere is (2/3)* π * r^3. Substituting 10 in for r, we get that the volume of the bucket is 2000/3π. We divide 1500π by 2000/3π to get 9/4, but Brad can't make 1/4 of a trip to the well and get water, so the answer is 3 trips.
I want to politely tell you, Mr. Guest, that many of my friends at my school would have already told you to "---- off". We're not your personal slaves, we can do whatever we want. We don't have to answer your questions, and YOU need to learn some discipline. I expect you are some spoiled rich kid who gets whatever they want. Well then, welcome to the real world, where no one gives a c**p about what you think.