If the two sides of a right triangle are 3cm and 4cm respectively, what is its area?
一个直角三角形的两条直角边分别是3cm和4cm，它的面积是多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>