The radius of a circular lawn is 10 meters. If the lawn is 15 yuan per square meter, how much is the total cost of paving the lawn?
一块圆形草坪的半径是10米，如果每平方米草坪15元，铺这块草坪共需多少元？
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100 * 15</gadget>
<output>4_710</output>

<result>4_710</result>