[tex]\qquad\qquad\huge\underline{{\sf Answer}}♨[/tex]
According to angle sum property of a quadrilateral, Sum of all angles of a quadrilateral measures 360°
So, let's solve for x ~
[tex]\qquad \tt \dashrightarrow \:68 + 126 + 106 + x = 360[/tex]
[tex]\qquad \tt \dashrightarrow \:300+ x = 360[/tex]
[tex]\qquad \tt \dashrightarrow \:x = 360 - 300[/tex]
[tex]\qquad \tt \dashrightarrow \:x = 60 \degree[/tex]
