A square swimming pool has a side length of 15 meters and a depth of 3 meters. How many square meters need to be painted to paint the inner layer of the swimming pool with water-repellent paint?
一个正方形游泳池，边长是15米，深3米，要把游泳池内层涂上放水油漆，需要粉刷多少平方米？
<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<gadget id="calculator">15 * 3 * 4</gadget>
<output>180</output>

<gadget id="calculator">225 + 180</gadget>
<output>405</output>

<result>405</result>