If the lengths of two adjacent sides of an isosceles triangle are 3 cm and 6 cm, what is its perimeter in cm?
一个等腰三角形两条邻边的长度是3厘米和6厘米，它的周长是多少厘米．
<gadget id="calculator">6 + 6 + 3</gadget>
<output>15</output>

<result>15</result>