There is a point O in the middle of the triangle, and the length of the perpendicular segment from point O to the three sides of the triangle is 4cm, and the perimeter of the triangle is 36cm, find the area of the triangle.
三角形中间有一点O，点O到三角形的三条边的垂线段长都是4cm，又知三角形的周长是36cm，求三角形的面积．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 36 * 4</gadget>
<output>72</output>

<result>72</result>