How to Calculate the Area of a Circle Using Radius

Learn the method to find the area of a circle when the diameter isn't available, using just the radius or circumference.

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To find the area of a circle without the diameter, you can use the radius. The formula is A = πr², where 'A' is the area and 'r' is the radius. If you only have the circumference (C), you can find the radius by using the formula r = C / (2π). Once you have the radius, you can then substitute it into the area formula.

FAQs & Answers

  1. What is the formula for the area of a circle? The area of a circle is given by the formula A = πr², where 'A' is the area and 'r' is the radius.
  2. How do you find the radius of a circle from its circumference? You can find the radius by using the formula r = C / (2π), where 'C' is the circumference of the circle.
  3. Can I calculate the area of a circle without knowing the diameter? Yes, you can calculate the area if you know the radius or circumference of the circle.
  4. Why is the radius important in circle calculations? The radius is essential because it is the key measurement needed to calculate the area and other properties of a circle.