AFOQT Practice Test

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Prepare for the AFOQT Test. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

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What is the formula for the circumference of a circle?

πr²
2πr
πd
4πr

The correct answer is: 2πr

The formula for the circumference of a circle is given by 2πr, where r represents the radius of the circle. This formula arises from the definition of circumference as the distance around a circle. The circumference can also be expressed in terms of the diameter (d) of the circle, as the diameter is twice the radius (d = 2r). Therefore, substituting this relationship into the formula gives an alternative expression of circumference as πd. In summary, the formula 2πr is derived directly from the geometric properties of a circle, reflecting how the radius plays a crucial role in determining the total distance around the circle. The options involving πr² refer to the area of the circle, and 4πr does not correspond to any standard measurement associated with circles.