The perimeter of a triangle is 16.4 centimeters, and the first and second sides are both 5 centimeters. How long is the third side in centimeters?
一个三角形的周长是16.4厘米，其中第一、二两条边都是5厘米，第三条边长多少厘米？
<gadget id="calculator">16.4 - 5 - 5</gadget>
<output>6.4</output>

<result>6.4</result>