A triangular lawn has a base length of 20 meters and a height of 15 meters. What is the area of the lawn in square meters?
一块三角形草地，底长20米，高长15米，这块草地的面积是多少平方米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 20 * 15</gadget>
<output>150</output>

<result>150</result>