The base of the triangle is 15 cm and the height is twice the base. What is the area of the triangle in square centimeters?
三角形的底是15厘米，高是底的2倍，三角形的面积是多少平方厘米？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">30 * (15/2)</gadget>
<output>225</output>

<result>225</result>