A cylindrical reservoir has an inner diameter of 20 meters and a depth of 2 meters. The inner wall and bottom of the pool are inlaid with tiles. What is the area of the tiled part?
一个圆柱形蓄水池底面内直径是20米，深2米，在池的内壁与底面镶上瓷砖，镶瓷砖部分的面积是多少平方米？
<result>15.7</result>