The diameter of the base of a circle is 4 decimeters, and the side view is a square. What is the volume of this cylinder in cubic decimeters?
一个圆的底面直径是4分米，侧面展开图是一个正方形，这个圆柱的体积是多少立方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">3.14 * 4 * 12.56</gadget>
<output>157.7536</output>

<result>157.7536</result>