The area of a sector is (3/5) the area of a circle with the same radius, and the length of the arc contained in this sector is the circumference of the circle with the same radius
一个扇形的面积是同半径圆面积的(3/5)，这个扇形所含圆弧的长是同圆半径圆周长多少
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>