The number of diagonals of a polygon of n sides is given by the formula z=n(n-3)/2. If a polygon has twice as many diagonals as sides, how many sides does it have? Choose the correct choice from the following options:
A) 3 B) 5 C) 6 D) 7 E) 8
z=n(n-3)   z=2*n   2n=n(n-3)   =&gt;2=n-3   =&gt;n=5   Answer 5
<result>B</result>
The number of diagonals of a polygon of n sides is given by the formula z=n(n-3)/2. If a polygon has twice as many diagonals as sides, how many sides does it have?