An isosceles triangle has two sides of 4cm and 9cm respectively, what is the perimeter of this triangle?
一个等腰三角形，有两条边分别是4cm和9cm，这个三角形的周长是多少．
<gadget id="calculator">9 + 9 + 4</gadget>
<output>22</output>

<result>22</result>