The circle is present in different situations that we experience. We just have to pay attention and we soon notice your presence. The wheel, the steering wheel, the plates, some squares are examples of the circular shape in our daily lives. To deal with this geometric shape we need to learn how to calculate its length.
Sr. José has always liked to walk around the court where he lives. This court has a square format, with each side measuring 40 meters, so we know that a complete lap in this court corresponds to 160 meters, because 4 * 40 = 160.
Near Mr. José's house, a square was inaugurated with a leisure and running track in a circular format. Trying to figure out a way to measure how many meters he will travel in a complete loop on the circular track, he found an interesting way to calculate that distance. Mr. José explained that for the measurement he would need to determine the measure of the square's radius, which is the distance between the center of the square and the running track.
In his research he found that he would need to multiply the radius measure by 2 and by a number called pi (symbol: π). The number pi is present in all calculations involving circular shapes and its unique value equals 3.14. Therefore, in order to determine the length of this square and all the circular ones, we performed the following calculation:
C = 2 * π * r
C: length
π: 3,14
r: radius measurement
The measure of the radius of this square is 50 meters, so:
C = 2 * 3.14 * 50
C = 314 meters
Therefore, a complete turn in this square corresponds to a distance of 314 meters.
by Mark Noah
Mathematical
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