Question

Difficulty: MediumCircles

Match each circle-related calculation on the left to its correct numerical value on the right.

  • Area of a circle with a radius of 5525π25\pi
  • Circumference of a circle with a diameter of 101010π10\pi
  • Radius of a circle with an area of 100π100\pi1010
  • Diameter of a circle with a circumference of 12π12\pi1212

Answer

Area with radius 5 matches to 25π; Circumference with diameter 10 matches to 10π; Radius of area 100π matches to 10; Diameter of circumference 12π matches to 12.
Each match is verified by accurately applying the formulas A=πr2A = \pi r^2 and C=πdC = \pi d to either solve for the resulting property or to work backwards to find the missing dimension.

Step-by-Step Solution

1
Calculate the area for the first description.
Area = 25π25\pi
The formula for the area of a circle is A=πr2A = \pi r^2. Substituting r=5r = 5 yields 25π25\pi.
2
Calculate the circumference for the second description.
Circumference = 10π10\pi
The formula for circumference is C=πdC = \pi d. Substituting d=10d = 10 yields 10π10\pi.
3
Solve for the radius in the third description.
Radius = 1010
Given area A=100πA = 100\pi, use 100π=πr2100\pi = \pi r^2 to find that r2=100r^2 = 100, so r=10r = 10.
4
Solve for the diameter in the fourth description.
Diameter = 1212
Given circumference C=12πC = 12\pi, use 12π=πd12\pi = \pi d to determine that d=12d = 12.

Key Concept

Calculating area, circumference, radius, and diameter of a circle using fundamental geometry formulas.
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