Given,
The measure of two angles of the triangle is 80 degree and 60 degree.
Required:
The measure of angle X.
As known that,
The sum of all interior angles of the triangle is 180 degree.
[tex]\begin{gathered} \angle X+\angle Y+\angle Z=180^{\circ} \\ \operatorname{\angle}X+60^{\operatorname{\circ}}+80^{\operatorname{\circ}}=180^{\operatorname{\circ}} \\ \operatorname{\angle}X+140^{\operatorname{\circ}}=180^{\operatorname{\circ}} \\ \angle X=180^{\circ}-140^{\operatorname{\circ}} \\ \angle X=40^{\operatorname{\circ}} \end{gathered}[/tex]
Hence, the measure of angle X is 40 degree.
