As given by the question
There are given that in the right triangle DEF, angle D is 90 degrees and angle f is 12 degrees less than angle E.
Now,
The sum of the three measures of a triangle is always 180 degree
So,
[tex]m\angle D+m\angle E+m\angle F=180[/tex]
Where angle D is 90 degree
Then,
[tex]\begin{gathered} m\angle D+m\angle E+m\angle F=180 \\ 90+m\angle E+m\angle F=180 \\ m\angle E+m\angle F=90 \end{gathered}[/tex]
Also we are given that
[tex]\begin{gathered} F+12=2E \\ F=2E-12 \end{gathered}[/tex]
Therefore, substituting for F back into E+F=90
Then,
[tex]\begin{gathered} E+(2E-12)=90 \\ 3E-12=90 \\ 3E=102 \\ E=34 \end{gathered}[/tex]
So, angle E is 34 degrees, which is the answer.