The ratio of the lengths of the three sides of a triangle is 2:3:4, and the longest side is 36 cm. What is the perimeter of the triangle in cm?
一个三角形三条边的长度比2：3：4，其中最长的边是36cm，这个三角形的周长是多少cm．
<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">36 / (4/9)</gadget>
<output>81</output>

<result>81</result>