The height of a cylinder is 8 cm and its radius is 2 cm. If it is split in half along the diameter of the base, what is the area of the split face?
圆柱的高是8厘米，半径是2厘米，沿着底面直径把它劈成两半，劈开面的面积是多少平方厘米．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>