Remember: Area of a circle is A = πr²
First, we'll find the area of the larger circle. Using the formula for the area of a circle, we would need to divide the diameter, 10.5 in half to get the radius.
→10.5 ÷ 2 = 5.25
Next, we need to square that number.
→5.25² = 27.5625 (Yes, the number is quite long)
Then, we'll need to multiply that number to π, or 3.14.
→27.5625 × 3.14 = 86.54625 (Phew)
This is the area for your large circle.
Repeating the steps from the larger circle, let's find the smaller circle.
1. 4.5 ÷ 2 = 2.25
2. 2.25² = 5.0625
3. 5.0625 × 3.14 = 15. 89625
Finally, subtract the two numbers together:
→ 86.54625 - 15.89625 = 70.65
Let's round.... To 70.7
Your final answer is 70.7 cm²
I hope this helps!
