A wire 320 in. long is cut into two pieces. one piece is formed into a square and the other into a circle. if the two figures have the same area, what are the lengths of the two pieces of wire (to the nearest tenth of an inch)? circle in square in

Respuesta :

The area of a circle can be computed from the circumference (c) as
.. Acircle = c^2/(4π)

The area of a square can be computed from its perimeter (p) as
.. Asquare = (p/4)^2 = p^2/16

These are equal when
.. Acircle = Asquare
.. c^2/(4π) = p^2/16
.. c^2/p^2 = (4π)/16
.. c/p = (√π)/2

The total length is 320 inches, so ...
.. wire for circle = ((√π)/2)/(1 +(√π)/2)*320 in ≈ 150.3 in
.. wire for square = 320 in - wire for circle ≈ 169.7 in

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In the graph, (x, y) represents (circle wire, square wire).
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