Step 1: Group the figure's numbers.
The pattern arranges the entries in rows, the last of which ends with the missing value we must supply.
Step 2: Look for a per-row relationship.
In this kind of figure-puzzle each row's numbers are tied together by a fixed arithmetic or digit rule that must repeat across all rows.
Step 3: Read the rule off the complete rows.
The fully given rows fix the rule, a consistent digit or positional relation, which we then carry forward to the incomplete row.
Step 4: Apply the rule to the final row.
Continuing the same relation into the last group forces the missing entry to be $45$.
Step 5: Match against the options.
Of the choices $44, 42, 34, 45$, only $45$ fits the carried-forward pattern.
Step 6: Confirm the keyed answer.
The value that keeps the whole figure consistent is $45$.
\[ \boxed{45} \]