If the two sides of a triangle are 30 centimeters and 40 centimeters respectively, the length of the third side must be selected from the following three quantities, and only how many centimeters can be selected
如果一个三角形的两条边分别是30厘米、40厘米，第三条边的长度要在下面的三个量中选出，只能选多少厘米
<result>50</result>