The radius of the base of a cylinder is 4 cm, and its side view is a square, what is its side area in square centimeters?
一个圆柱底面半径是4厘米，它的侧面展开图是一个正方形，它的侧面积是多少平方厘米？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">3.14 * 8</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 * 25.12</gadget>
<output>631.0144</output>

<result>631.0144</result>