section of chimney is 0.8 meters long, and the circumference of the bottom surface is 15.7dm. How many square meters of iron sheets are needed to make such two sections of chimneys?
一节烟囱长0.8米，底面周长15.7dm，做这样的两节烟囱需要多少平方米铁皮？
<gadget id="calculator">125.6 * 2</gadget>
<output>251.2</output>

<result>251.2</result>