Remember the Property of Exponents:-
[tex]\sf{(a^b)^n=a^{bn}}}\longleftarrow{multiply~the~powers}}[/tex]
Multiply the powers:-
[tex]\sf{(4a^2)^8}[/tex]
Multiply 2 times 8:-
[tex]\bigstar{\boxed{\pmb{4a^{16}}}}[/tex]
Hope everything is clear; if you need any explanation/clarification. kindly let me know, and I'll comment and/or edit my answer :)
