O is the center of the circle in the diagram below.
What is its area?
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O is the center of the circle in the diagram below.
What is its area?
Remember that the formula for the area of a circle is
πR²
We insert the known data:
π3²
π9
cm²
A circle has a circumference of 31.41.
What is its radius?
Look at the diagram carefully! The line from center O to the edge is labeled "3" - this is the radius because it goes from center to circumference.
Using π gives the exact answer! Writing is more precise than 28.26, and many math problems expect the exact form.
The ² means squared or "times itself". So r² = r × r. When r = 3, then r² = 3 × 3 = 9.
Yes! Since we're measuring area, use square units like cm², m², or just "square units" if no specific unit is given.
You might have used the circumference formula C = 2πr by mistake! Remember: circumference uses 2πr, but area uses πr².
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