The lengths of two sides in an isosceles triangle are 4 cm and 9 cm respectively. What is the perimeter of this isosceles triangle?
一个等腰三角形中有两边的长度分别是4厘米，9厘米，这个等腰三角形的周长是多少？
<gadget id="calculator">9 + 9 + 4</gadget>
<output>22</output>

<result>22</result>