Circles are round shapes, like a pizza or a clock. In these worksheets, we will practice finding the area of each lamina (which means a thin, flat, circular shape), calculating the radius of each lamina, and finding the area of the shaded part in each figure. Let’s get started!
- Area of a Circle: To find the area of a circle, we need to know its radius. The radius is the distance from the center of the circle to its edge. Once we have the radius, we can use the following formula to find the area:
Area = π × (radius × radius)
Here, π (pi) is a special number, approximately equal to 3.14. So, if you have a circle with a radius of 2 units, the area would be:
Area = 3.14 × (2 × 2) = 3.14 × 4 = 12.56 square units
- Calculate the radius of each lamina: In the worksheet, you will see circular shapes (laminas) with different measurements. Your task is to find the radius of each lamina. You may be given the diameter (which is the distance across the circle, passing through the center) or the circumference (which is the distance around the circle, like a perimeter). If you have the diameter, just divide it by 2 to find the radius. If you have the circumference, use the following formula to find the radius:
Radius = Circumference / (2 × π)
- Find the area of the shaded part in each figure: In some of the figures, you will see shaded parts within the laminas. To find the area of the shaded part, first, calculate the area of the larger circle and then the area of the smaller circle. Subtract the area of the smaller circle from the area of the larger circle to get the area of the shaded part.
For example, if the larger circle has a radius of 5 units and the smaller circle has a radius of 2 units:
Area of larger circle = 3.14 × (5 × 5) = 3.14 × 25 = 78.5 square units Area of smaller circle = 3.14 × (2 × 2) = 3.14 × 4 = 12.56 square units Area of shaded part = 78.5 – 12.56 = 65.94 square units
In the Area of a Circle Worksheet, practice calculating the radius and finding the area of each lamina, as well as the shaded parts. Enjoy practicing and learning more about circles!
Printable Area Of A Circle Worksheets