Solution:
Given that;
The measure of angle A is 59.5° and angle B is supplemental to A, i.e.
To find the measure of angle B,
For supplementary angles, they sum up to 180°.
[tex]\begin{gathered} m\angle A+m\angle B=180\degree\text{ \lparen Supplementary angles\rparen} \\ 59.5\degree+m\angle B=180\degree \\ Collect\text{ like terms} \\ m\angle B=180\degree-59.5\degree=120.5\degree \\ m\angle B=120.5\degree \end{gathered}[/tex]
Hence, the measure of angle B is 120.5°
