The diameter of the small circle is 4cm, the diameter of the large circle is 8cm, what is the area of the small circle equal to the area of the large circle
小圆的直径是4cm，大圆的直径是8cm，小圆的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>