It is known that one side of an isosceles triangle is 3cm and the other side is 7cm. What is the perimeter of this triangle?
已知一个等腰三角形的一边是3cm，一边是7cm，这个三角形的周长是多少？
<gadget id="calculator">7 + 7 + 3</gadget>
<output>17</output>

<result>17</result>