In an isosceles triangle, two sides are known to be 8 cm and 4 cm long respectively, what is the perimeter of this isosceles triangle in cm.
在一个等腰三角形中，已知两条边分别长8厘米和4厘米，这个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>