To make a triangular traffic warning sign with a base of 8 decimeters and a height of 6.5 decimeters, if the material cost per square meter is 140 yuan, how much is the material cost for such a sign?
要做底是8分米，高是6.5分米的三角形交通警示标志，如果每平方米的材料费用是140元，那么做一块这样的标志牌所需材料费是多少元？
<gadget id="calculator">6.5 / 2 / 100</gadget>
<output>0.0325</output>

<gadget id="calculator">8 * 0.0325 * 140</gadget>
<output>36.4</output>

<result>36.4</result>