There are 1 small sticks with a length of 4 cm and a length of 8 cm, and a small stick is used to form an isosceles triangle. What is the perimeter of the formed isosceles triangle in centimeters?
现有4厘米长8厘米长的小棒各1根，再配一根小棒围成一个等腰三角形，围成的等腰三角形的周长是多少厘米．
<gadget id="calculator">8 + 8 + 4</gadget>
<output>20</output>

<result>20</result>