Deterministic finite automata (DFA) (have odd length or end with aaa) Is my attempt is true or where am I wrong?
DFA : The set of strings over $\{a, b\} $ that have odd length or end with $aaa$.


Your DFA is correct; it consists of eight states, as you have, one for every combination of "Is the string odd or even length?" and "Have I most recently seen 0,1,2, or 3+ consecutive A's"?  You can arrange your DFA like this for easier readability:

And there's an equivalent DFA with fewer states that might be easier to check:

