After assembling a cylinder into an approximate cuboid along the radius and high cut of the bottom surface, two surfaces are added, which are exactly squares with a perimeter of 28 cm. Find the volume of the original cylinder?
将一个圆柱沿着底面半径和高切拼成一个近似的长方体后，增加了两个面，这两个正好是周长为28厘米的正方形，求原来圆柱的体积？
<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<gadget id="calculator">7 ** 2</gadget>
<output>49</output>

<gadget id="calculator">3.14 * 49 * 7</gadget>
<output>1_077.02</output>

<result>1_077.02</result>