There is a largest circle in a square with an area of 30 square centimeters. Find the area of the circle in square centimeters (take 3.14 for π).
一个面积30平方厘米的正方形中有一个最大的圆，求该圆的面积是多少平方厘米(π取3.14)．
<gadget id="calculator">3.14 * 7.5</gadget>
<output>23.55</output>

<result>23.55</result>