The radius of the large circle is equal to the diameter of the small circle, and the area of the small circle is 60 square centimeters smaller than the large circle. What is the area of the small circle?
大圆的半径等于小圆的直径，小圆的面积比大圆小60平方厘米，小圆的面积是多少？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">60 / 3</gadget>
<output>20</output>

<result>20</result>