The side view of a cylinder is a square. The perimeter of the square is 62.8dm. What is the radius of the base of the cylinder in decimeters?
一个圆柱的侧面展开图是一个正方形，这个正方形的周长是62.8dm，这个圆柱的底面半径是多少分米．
<gadget id="calculator">62.8 / 4</gadget>
<output>15.7</output>

<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<result>2.5</result>