Complementay angles: we say that two angles are complementary angles when they add up to 90°
In this case we have the complementary angles <4 and <5, so they sum up 90°:
[tex]<4+<5=90[/tex]Now, the question says that <4 = 85, so if replace this in the last equation we have:
[tex]\begin{gathered} <4+<5=90 \\ 85+<5=90 \\ <5=90-85=5 \end{gathered}[/tex]Answer: <5 = 5