The diameter of a circular garden is 16 meters, three-eighths of which are planted with roses. How big is the area where the roses are planted?
一个圆形花园的直径是16米，其中八分之三的面积种了玫瑰．种玫瑰的面积有多大？
<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">3.14 * 64 * (3/8)</gadget>
<output>75.36</output>

<result>75.36</result>