Find the area of a circle quiz for students. This is a math test that features pictures of circles showing the radius of each. The formula for finding the area of a circle is pie times the radius squared. With this formula in mind it is easy to find the area of any circle. Remember the radius is half the diameter of the circle drawn right from the middle. With the equation for area of a circle in mind, solve these quizzes and get instant feedback as you take the test. This geometry exercise is for students in the following grades: 4th, 5th, 6th, and 7th grades. Be over and done with this question: how do you figure out the area of a circle?