A triangular warning sign has a base of 1.8 meters and a height of 1.5 meters. What is the area of this warning sign?
一块三角形警示牌的底是1.8米，高是1.5米．这块警示牌的面积是多少？
<gadget id="calculator">1.5 / 2</gadget>
<output>0.75</output>

<gadget id="calculator">1.8 * 0.75</gadget>
<output>1.35</output>

<result>1.35</result>