If the length, width and height of a cuboid are 6cm, 3cm and 2.5cm respectively, what is its surface area in cm**2.
一个长方体的长、宽、高分别是6cm、3cm、2.5cm，那么它的表面积是多少cm**2．
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">6 * 2.5</gadget>
<output>15</output>

<gadget id="calculator">3 * 2.5</gadget>
<output>7.5</output>

<gadget id="calculator">18 + 15 + 7.5</gadget>
<output>40.5</output>

<gadget id="calculator">40.5 * 2</gadget>
<output>81</output>

<result>81</result>