If the base of a triangle is 5 cm and the height is twice the base, what is its area?
一个三角形的底是5厘米，高是底的2倍，那么它的面积是多少．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">5 * 2 * (5/2)</gadget>
<output>25</output>

<result>25</result>