Given that the sides of an isosceles triangle are 4cm and 8cm, what is the perimeter of the triangle?
已知一个等腰三角形两边为4cm，8cm，这个三角形的周长是多少．
<gadget id="calculator">4 + 4 + 4 + 4 + 4</gadget>
<output>20</output>

<result>20</result>