The radius of the base of a cylinder is 5 cm and the height is 12 cm. What is the perimeter of its side view?
一个圆柱的底面半径是5厘米，高是12厘米，它的侧面展开图的周长是多少．
<gadget id="calculator">3.14 * 2 * 5</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 + 12</gadget>
<output>43.4</output>

<gadget id="calculator">43.4 * 2</gadget>
<output>86.8</output>

<result>86.8</result>