Answer
The IUPAC name of the alkene is $7-methylenecyclohepta-1,3,5-triene$
Work Step by Step
The compound has 7 carbon atoms in its longest carbon ring containing the double bond ($hept-$). It has a $methylene-$ substituent at position 7, and 3 double bonds at positions 1,3 and 5. So, the IUPAC name of the alkene is $7-methylenecyclohepta-1,3,5-triene$
