The lengths of two sides of an isosceles triangle are 3 cm and 7 cm respectively, what is the perimeter of the triangle in cm?
等腰三角形其中两边长分别为3厘米和7厘米，这个三角形的周长为多少厘米．
<gadget id="calculator">7 + 7 + 3</gadget>
<output>17</output>

<result>17</result>