Question

Difficulty: MediumPerimeter and Area of 2D Figures

A circular security zone has a circumference of 16π16\pi meters. What is the area of this zone in square meters?

  1. A
    16π16\pi
  2. 64π64\piAnswer
  3. C
    128π128\pi
  4. D
    256π256\pi

Answer

64π64\pi
To find the area, the radius of the circle must first be determined using the circumference formula (C=2πrC = 2\pi r). Setting the given circumference equal to the formula (16π=2πr16\pi = 2\pi r) gives a radius of 88 meters. The area is then calculated using the formula A=πr2A = \pi r^2, which results in π(8)2=64π\pi(8)^2 = 64\pi square meters.

Step-by-Step Solution

1
Identify the formula for circumference to solve for the radius.
C=2πr=16πC = 2\pi r = 16\pi
The radius is required to calculate the area of the circle.
2
Solve for the radius (rr).
r=8r = 8 meters
Dividing both sides of the equation by 2π2\pi isolates the radius.
3
Apply the area formula for a circle using the found radius.
A=πr2=π(8)2=64πA = \pi r^2 = \pi(8)^2 = 64\pi square meters
Substituting the radius (88) into the area formula yields the final required value.

Key Concept

Calculating the area of a circle by first deriving its radius from a given circumference.
Estimated Time:45s
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