triangle is surrounded by a piece of iron wire. The ratio of the lengths of the three sides is 3:5:7. The length of the shortest side is known to be 12 cm. How many centimeters is the total length of this piece of wire?
用一段铁丝围成一个三角形，三条边长度的比是3：5：7，已知最短边的长度是12厘米，这段铁丝一共长多少厘米？
<gadget id="calculator">3 + 5 + 7</gadget>
<output>15</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

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

<result>60</result>