The volume difference between a cylinder and a cone with the same base and height is 6.28 cubic centimeters. What is the sum of the volumes of the cylinder and the circle?
等底等高的一个圆柱体和一个圆锥体的体积差是6.28立方厘米，圆柱与圆体积和是多少
<gadget id="calculator">6.28 / 2</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<gadget id="calculator">3.14 + 9.42</gadget>
<output>12.56</output>

<result>12.56</result>