Practice Area of a Circle in Math
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The amount of space enclosed inside a circle, calculated as \pi times the square of the radius.
Imagine cutting a pizza into many thin slices and rearranging them into a shape that looks like a rectangle. The 'height' of that rectangle is the radius r, and the 'width' is half the circumference (\pi r). So the area is r \times \pi r = \pi r^2.
Example 1
easyFind the area of a circle with radius 6 cm. Leave your answer in terms of \pi.
Example 2
mediumFind the area of a semicircle with diameter 20 cm. Give your answer to one decimal place.
Example 3
hardA circular garden has an area of 154 mยฒ. Find the radius of the garden. Use \pi \approx \frac{22}{7}.
Example 4
mediumA circular pond has radius 6 m. A path around it extends the outer radius to 9 m. Find the area of the path.