The circumference of the base of a cylinder is 12.56dm, and the height is equal to the radius of the base. What is its volume in dm**3.
一个圆柱的底面周长是12.56dm，高等于底面半径，它的体积是多少dm**3．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>