The ratio of the area of the large circle to the area of the small circle is 9:4, and the difference between the circumference of the large circle and the circumference of the small circle is 12 decimeters. What is the circumference of the large circle in decimeters?
大圆面积与小圆面积的比是9：4，大圆周长与小圆周长的差是12分米，则大圆周长是多少分米．
<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<result>36</result>