First you find out the Area of the square itself which is 100cm² (squared). Then you Find the Area of the circle. The formula to find the area of a circle is π × Radius². So you find the diameter of the circle (which is 10) and divide that by 2 to find the radius. So the radius is 5 but then you need to square 5 which is 25. Then you multiply 25 with pi which is 78.5 so the area of the circle is 78.5cm². Now what you have to do is subtract the area of the square and the area of the circle to find the area of the shaded region. 100-78.5 is 21.5cm ² and that is the answer.
