Draw a circle with a radius of 4 cm on a drawing at a scale of 1:4. What is the area of the circle on the drawing in square centimeters?
把一个半径是4厘米的圆，按1：4的比例尺画在图纸上，图纸上圆的面积是多少平方厘米．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 * (1/4)</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

<result>3.14</result>