Lijiazhuang decided to dig a cylindrical pool with a radius of 5m and a depth of 4m. How many square meters does this pool cover?
李家庄决定挖一个半径是5m，深4m的圆柱水池．这个水池的占地面积是多少平方米？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>