The perimeter of a square is equal to the perimeter of a circle, and the radius of the circle is 15 cm. What is the side length of the square in cm?
一个正方形的周长和一个圆的周长相等，圆的半径是15厘米，正方形的边长是多少厘米？
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3.14 * 15 * (1/2)</gadget>
<output>23.55</output>

<result>23.55</result>