Complementary angles are two angles whose measures add up to 90 degrees. Given that \( m∠2 = 85° \), you can find \( m∠1 \) using the following equation:
\[ m∠1 + m∠2 = 90° \]
Substituting the value of \( m∠2 \):
\[ m∠1 + 85° = 90° \]
Now, solve for \( m∠1 \):
\[ m∠1 = 90° - 85° = 5° \]
Thus, the value of \( m∠1 \) is \( 5° \).