A triangular traffic sign with a base of 8 decimeters and a height of about 7 decimeters. What is its approximate area in square centimetres?
一块三角形的交通标志牌，底是8分米，高大约是7分米．它的面积大约是多少平方分米？
<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">8 * (7/2)</gadget>
<output>28</output>

<result>28</result>