cylinder and a cone have the same volume, the radius of the base of the cylinder is 1/2 that of the cone, and the height of the cylinder is equal to that of the cone.
圆柱和圆锥体积相等，圆柱的底面半径是圆锥的(1/2)，圆柱的高是圆锥的多少．
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / (3/4)</gadget>
<output>4/3 = around 1.333333</output>

<result>4/3 = around 1.333333</result>