The two adjacent sides of an isosceles triangle are 6 cm and 3 cm respectively. What is the perimeter of this triangle in centimeters?
等腰三角形相邻两条边分别是6厘米，3厘米．这个三角形的周长是多少厘米？
<gadget id="calculator">3 + 3 + 3 + 3 + 3</gadget>
<output>15</output>

<result>15</result>