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 multiplied by itself ($r \times r$).
Important Note: If the problem gives you the
diameter (the line all the way across), you must divide it by 2 to get the radius first.
Here are the step-by-step solutions for each circle on the right side of the page:
Circle 1 (Top)
*
Given: The line goes all the way across the circle, so the
Diameter = 6 cm.
*
Find Radius: $6 \div 2 = 3$ cm.
*
Calculate Area:
* $Area = 3.14 \times 3^2$
* $Area = 3.14 \times 9$
* $Area = 28.26$
*
Answer: 28.26 cm²
Circle 2 (Second from top)
*
Given: The line goes from the center to the edge, so the
Radius = 8 cm.
*
Calculate Area:
* $Area = 3.14 \times 8^2$
* $Area = 3.14 \times 64$ *(because $8 \times 8 = 64$)*
* $Area = 200.96$
*
Answer: 200.96 cm²
Circle 3 (Third from top)
*
Given: The line goes from the center to the edge, so the
Radius = 2 cm.
*
Calculate Area:
* $Area = 3.14 \times 2^2$
* $Area = 3.14 \times 4$ *(because $2 \times 2 = 4$)*
* $Area = 12.56$
*
Answer: 12.56 cm²
Circle 4 (Bottom)
*
Given: The line goes all the way across the circle, so the
Diameter = 10 cm.
*
Find Radius: $10 \div 2 = 5$ cm.
*
Calculate Area:
* $Area = 3.14 \times 5^2$
* $Area = 3.14 \times 25$ *(because $5 \times 5 = 25$)*
* $Area = 78.5$
*
Answer: 78.5 cm²
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Final Answer:
Circle 1: 28.26 cm²
Circle 2: 200.96 cm²
Circle 3: 12.56 cm²
Circle 4: 78.5 cm²
Parent Tip: Review the logic above to help your child master the concept of find the area of a circle worksheet.
