If 2△3=2+3+4=9, 5△4=5+6+7+8=26, according to this rule, 6△6=how much.
若2△3=2+3+4=9，5△4=5+6+7+8=26，按此规律，6△6=多少．
<gadget id="calculator">6 + 7 + 8 + 9 + 10 + 11</gadget>
<output>51</output>

<result>51</result>