Step-by-step explanation:
Let the measure of the third angle of the triangle be x.
As we know that,
Therefore,
[tex] \sf \longrightarrow {\angle{A}\ +\ \angle{B}\ +\ \angle{C}\ =\ 180^{\circ}} [/tex]
[tex] \sf \longrightarrow {85^{\circ}\ +\ 23^{\circ}\ +\ x\ =\ 180^{\circ}} [/tex]
[tex] \sf \longrightarrow {108^{\circ}\ +\ x\ =\ 180^{\circ}} [/tex]
[tex] \sf \longrightarrow {x\ =\ 180^{\circ}\ -\ 108^{\circ}} [/tex]
[tex] \bf \longrightarrow {\underline{x\ =\ 72^{\circ}}}\ \bigstar [/tex]
∴ Hence, the measure of the third angle of the triangle is 72°.