The perimeter of a triangle is 26cm, two of the sides are 8cm and 5.5cm, what is the length of the third side in cm?
一个三角形周长是26cm，其中两条边长分别是8cm和5.5cm，第三条边长是多少cm．
<gadget id="calculator">26 - 8 - 5.5</gadget>
<output>12.5</output>

<result>12.5</result>