So,
Let's draw the structures for the following hydrocarbons:
Cyclohexane
We can draw it using the fact that it is a cycloalkane with six carbons:
Cyclohexene
It also contains six carbons with a hexagonal form, but the difference is that there's double bond on it:
Benzene
It has six carbons but there's an alternating double bond as follows:
Toluene
It has the same structure as benzene but it is bonded to a methyl group outside the benzene:
