A triangular vegetable field has a base length of 12m and a height of 5m. What is the area of this vegetable field?
一块三角形的菜地，底边长12m，高是5m．这块菜地的面积是多少？
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">12 * (5/2)</gadget>
<output>30</output>

<result>30</result>