The ratio of the area of a circle with a radius of l cm to the area of a square with a side length of 1 cm is π:
半径为l厘米的圆的面积与边长为1厘米的正方形的面积之比为π：多少
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<result>1</result>