If Angle A is a complement to Angle B, then mIf we know the value of m[tex]\begin{gathered} m\measuredangle a+m\measuredangle b=90 \\ 31+m\measuredangle b=90 \\ m\measuredangle b=90-31 \\ m\measuredangle b=59 \end{gathered}[/tex]The measure of Angle B is 59°,