A triangle has a base of 18 cm and a height of 15 cm. What is its area in square centimeters?
一个三角，底18厘米，高15厘米，它的面积是多少平方厘米．
<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">18 * (15/2)</gadget>
<output>135</output>

<result>135</result>