triangular flowerbed. There is a fountain in the flowerbed. The distance between the fountain and the three sides is 4 meters, and the perimeter is 32 meters. Find the area of the flowerbed.
三角形花圃，花圃中有一个喷泉，喷泉与三边的距离都是4米，又已知周长32米，求花圃面积．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">32 * 2</gadget>
<output>64</output>

<result>64</result>