How many centimeters of iron wire is needed to weld a rectangular teaching aid with a length of 6 cm, a width of 5 cm, and a height of 4 cm?
焊接一个长6厘米，宽5厘米，高4厘米的长方形教具，需用长多少厘米的铁丝．
<gadget id="calculator">6 + 5 + 4</gadget>
<output>15</output>

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

<result>60</result>