The perimeter of a rectangle is equal to the perimeter of a circle with a radius of 2.5 meters. It is known that the length of the rectangle is 4 meters. What is its width in meters?
一个长方形的周长与一个半径是2.5米的圆的周长相等，已知长方形的长是4米，它的宽是多少米？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 2.5 * 1</gadget>
<output>7.85</output>

<gadget id="calculator">7.85 - 4</gadget>
<output>3.85</output>

<result>3.85</result>