a=6m, b=3.4m, c=4m, find the surface area of the cuboid.
a=6米，b=3.4米，c=4米，求长方体的表面积．
<gadget id="calculator">6 * 3.4</gadget>
<output>20.4</output>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">3.4 * 4</gadget>
<output>13.6</output>

<gadget id="calculator">20.4 + 24 + 13.6</gadget>
<output>58</output>

<gadget id="calculator">58 * 2</gadget>
<output>116</output>

<result>116</result>