If the sides of an isosceles triangle are 6 cm and 3 cm long, what is its perimeter in cm?
一个等腰三角形的两条边分别长6厘米和3厘米，它的周长是多少厘米
<gadget id="calculator">6 + 6 + 3</gadget>
<output>15</output>

<result>15</result>