A circle is formed by a wire with a length of 16 decimeters, and the length of the joint is 0.3 decimeters. What is the area of the circle?
用一根长16分米的铁丝围成一个圆，接头处长0.3分米，这个圆的面积是多少？
<gadget id="calculator">16 - 0.3</gadget>
<output>15.7</output>

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

<gadget id="calculator">2.5 ** 2</gadget>
<output>6.25</output>

<gadget id="calculator">3.14 * 6.25</gadget>
<output>19.625</output>

<result>19.625</result>