The radius of the small circle is 2 cm, and the radius of the large circle is 4 cm. What is the area of the small circle equal to the area of the large circle?
小圆半径是2厘米，大圆半径是4厘米，小圆面积是大圆面积的多少
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>