Find the volume of the cylinder: the perimeter of the base is 50.24cm, and the height is 7cm.
求圆柱的体积：底面周长是50.24cm，高是7cm．
<gadget id="calculator">50.24 / 3.14 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">3.14 * 64 * 7</gadget>
<output>1_406.72</output>

<result>1_406.72</result>