To find the area of a circle, we use the formula:
Area = $\pi \times r^2$
Where:
* $\pi$ (pi) is approximately
3.14.
* $r$ is the
radius (the distance from the center to the edge).
* $r^2$ means radius $\times$ radius.
Important Note: If the problem gives you the
diameter (the full width across the circle), you must divide it by 2 to get the radius first.
Here are the step-by-step solutions for each problem on the worksheet:
1) Radius ($r$) = 6 m
* $r^2 = 6 \times 6 = 36$
* Area = $3.14 \times 36$
* Area =
113.04 m²
2) Radius ($r$) = 22 yd
* $r^2 = 22 \times 22 = 484$
* Area = $3.14 \times 484$
* Area =
1,519.76 yd²
3) Diameter = 5.2 ft. First, find the radius: $5.2 \div 2 = 2.6$ ft.
* $r^2 = 2.6 \times 2.6 = 6.76$
* Area = $3.14 \times 6.76$
* Area =
21.2264 ft²
4) Diameter = 21 ft. First, find the radius: $21 \div 2 = 10.5$ ft.
* $r^2 = 10.5 \times 10.5 = 110.25$
* Area = $3.14 \times 110.25$
* Area =
346.185 ft²
5) Radius ($r$) = 3.6 in
* $r^2 = 3.6 \times 3.6 = 12.96$
* Area = $3.14 \times 12.96$
* Area =
40.6944 in²
6) Diameter = 3.5 yd. First, find the radius: $3.5 \div 2 = 1.75$ yd.
* $r^2 = 1.75 \times 1.75 = 3.0625$
* Area = $3.14 \times 3.0625$
* Area =
9.61625 yd²
7) Radius ($r$) = 3 yd
* $r^2 = 3 \times 3 = 9$
* Area = $3.14 \times 9$
* Area =
28.26 yd²
8) Diameter = 12.2 ft. First, find the radius: $12.2 \div 2 = 6.1$ ft.
* $r^2 = 6.1 \times 6.1 = 37.21$
* Area = $3.14 \times 37.21$
* Area =
116.8394 ft²
9) Radius ($r$) = 4 in
* $r^2 = 4 \times 4 = 16$
* Area = $3.14 \times 16$
* Area =
50.24 in²
Final Answer:
1) 113.04 m²
2) 1,519.76 yd²
3) 21.2264 ft²
4) 346.185 ft²
5) 40.6944 in²
6) 9.61625 yd²
7) 28.26 yd²
8) 116.8394 ft²
9) 50.24 in²
Parent Tip: Review the logic above to help your child master the concept of area of circle worksheet.
