Hello!

Considering all the single and double(C-C and C-H) bonds for sigma and double bonds for pi in structures of Benzene-C6H6, Napthalene-C10H8 and Anthracene-C14H10 we get the following results

1. There are 3+9=12 sigma and 3 pi  bonds in Benzene.
2. There are 5+6+8=19 sigma and 5 pi  bonds in Napthalene.
3. There are 24+3-1=26 sigma  and 7 pi bonds in Anthracene.

Hope this helps you!