What is the area of a circle with a circumference of 31.4 cm? (2020)

Practice Questions

Q1
What is the area of a circle with a circumference of 31.4 cm? (2020)
  1. 25 cm²
  2. 50 cm²
  3. 75 cm²
  4. 100 cm²

Questions & Step-by-Step Solutions

What is the area of a circle with a circumference of 31.4 cm? (2020)
  • Step 1: Understand that the circumference of a circle is given by the formula C = 2πr, where C is the circumference and r is the radius.
  • Step 2: We know the circumference is 31.4 cm, so we can set up the equation: 31.4 = 2πr.
  • Step 3: To find the radius (r), we need to isolate r in the equation. First, divide both sides by 2π: r = 31.4 / (2π).
  • Step 4: Calculate the value of r. Using π ≈ 3.14, we find r = 31.4 / (2 * 3.14) = 31.4 / 6.28 = 5 cm.
  • Step 5: Now that we have the radius, we can find the area of the circle using the formula A = πr².
  • Step 6: Substitute the value of r into the area formula: A = π(5 cm)².
  • Step 7: Calculate the area: A = π * 25 cm² = 25π cm². Using π ≈ 3.14, we find A ≈ 25 * 3.14 = 78.5 cm².
  • Step 8: Therefore, the area of the circle is approximately 78.5 cm².
No concepts available.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely