Any point in straight line make a angle is 180 degree.
So at point R :
[tex]\begin{gathered} \angle3+136=180 \\ \angle3=180-136 \\ \angle3=44 \end{gathered}[/tex]
Similarly at point Q:
[tex]\begin{gathered} \angle2+104=180 \\ \angle2=180-104 \\ \angle2=76 \end{gathered}[/tex]
Sum of all three angle of any triangle is 180 then:
[tex]\begin{gathered} \angle1+\angle2+\angle3=180 \\ \angle1+76+44=180 \\ \angle1+120=180 \\ \angle1=180-120 \\ \angle1=60 \end{gathered}[/tex]
So the value is:
[tex]\begin{gathered} \angle1=60 \\ \angle2=76 \\ \angle3=44 \end{gathered}[/tex]
