The ratio of the lengths of the three sides of a triangle is 2:3:4, and the perimeter of the triangle is 27 cm. What is the longest side of this triangle in centimeters?
一个三角形三条边的长度比是2：3：4，这个三角形的周长是27厘米．这个三角形最长的边是多少厘米？
<gadget id="calculator">2 + 3 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">27 * (4/9)</gadget>
<output>12</output>

<result>12</result>