How many diagonals does a polygon with 19 sides have, if one of its vertices does not connect to any diagonal?
Select the correct option
A) 135  B) 125  C) 120  D) 110  E) 140
If I calculate it using the formulae, #diagonals = n (n-3)/2Each vertex sends of n-3 diagonals   n= 19-1 then 18*(18-3)/2= 
<gadget id="calculator">18*(18-3)/2</gadget>
<output>135</output>
135   Correct Option:	135
<result>A</result>
How many diagonals does a polygon with 19 sides have, if one of its vertices does not connect to any diagonal?