A triangular traffic sign has a base of 8 decimeters and a height of about 7 decimeters. If its front and back sides are painted, how many square decimeters will the painted area be?
一个三角形交通标志，它的底是8分米，高大约是7分米，如果给它的正反两面涂上油漆，涂漆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) * 2</gadget>
<output>56</output>

<result>56</result>