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Question

Difficulty: EasyCircles

A circular helipad has a diameter of 2020 meters. What is the area of the helipad in square meters?

  1. A
    20π20\pi
  2. B
    400π400\pi
  3. C
    10π10\pi
  4. 100π100\piAnswer

Answer

The correct area is 100π100\pi square meters.
The area of a circle is found using the formula A=πr2A = \pi r^2. Since the given diameter is 2020 meters, the radius is half of that amount, which is 1010 meters. Squaring the radius gives 100100, so the area is 100π100\pi square meters.

Step-by-Step Solution

1
Identify the given information and what needs to be found.
The diameter of the helipad is 2020 meters, and the area needs to be calculated.
Understanding the starting values is required to choose the correct geometric formulas.
2
Calculate the radius of the helipad.
The radius is half of the diameter: r=20÷2=10r = 20 \div 2 = 10 meters.
The standard formula for the area of a circle requires the radius, not the diameter.
3
Apply the area formula for a circle.
A=πr2=π(10)2=100πA = \pi r^2 = \pi (10)^2 = 100\pi square meters.
Squaring the radius and multiplying by π\pi yields the total area.

Key Concept

Calculating the area of a circle from its diameter.
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Topics

Circles

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