To make a triangular billboard with a base of 7m and a height of 2m, paint should be painted on both sides of the billboard. How many square meters is the painted area?
要制作一种底为7m，高为2m的三角形广告牌，要在广告牌的两面刷油漆，刷油漆的面积是多少平方米？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">7 * 1 * 2</gadget>
<output>14</output>

<result>14</result>