A triangular ruler has a base of 12 cm and a height of 5 cm. What is its area in square centimeters?
一把三角尺，底是12厘米，高是5厘米．它的面积是多少平方厘米？
<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>