After a grenade explodes, its effective killing radius is 10m. What is the killing area in m**2.
一种手榴弹爆炸后，有效的杀伤半径是10m．杀伤面积是多少m**2．
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<result>314</result>