A wire can form a rectangle with a length of 45 cm and a width of 15 cm. If two identical squares are to be formed, what is the side length of the square in cm?
一根铁丝可以围成一个长45厘米，宽15厘米的长方形，如果要围成两个相同的正方形，那么正方形的边长是多少厘米．
<gadget id="calculator">45 + 15</gadget>
<output>60</output>

<gadget id="calculator">2 / 2 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">60 * (1/4)</gadget>
<output>15</output>

<result>15</result>