We are given a circle with a partially shaded region. First, we need to determine the area of the whole circle. To do this, we need the measurement of the radius of the circle:
Use the Pythagorean theorem to solve for the other leg of the right triangle inside the circle:
5^2 = 3^2 + x^2 x = 4
The radius is 4 + 1 cm = 5 cm
So the area of the circle is A = pi*r^2 A = 3.14 * (5)^2 A = 25pi cm^2