Angles of the first line are the same of the second line because the lines are parallel and intersected by the same line
then
![\begin{gathered} x=\angle4 \\ 1=\angle5 \\ 2=\angle6 \\ 3=\angle7 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/4yc4a9jo2bv9umtktuynnkhkland6fjcf8.png)
then
![\angle4=106](https://img.qammunity.org/2023/formulas/mathematics/college/v2bivv7gqkqyyeqh54ixvxrgibkb6v90hx.png)
Now the opposite angles by the vertex like X and angle2 have the same value
then
![\angle2=106](https://img.qammunity.org/2023/formulas/mathematics/college/l0px77ppir4ieiljhpfdgxb4nzpfaqqj5e.png)
and
![\angle6=106](https://img.qammunity.org/2023/formulas/mathematics/college/x2gpgqu9lnv6wruqwi6bgk3f9xiyo4taot.png)
the adjacent angle of each angle make a straight angle then the sum is 180
now if we sum x and angle 1 we have 180
![x+\angle1=180](https://img.qammunity.org/2023/formulas/mathematics/college/5jmstimddd64mcaa3fcnrii5xzxkhqc42b.png)
we replace the value of x and solve for angle 1
![\begin{gathered} 106+\angle1=180 \\ \angle1=180-106 \\ \angle1=74 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/v3vq340tzgtbx229fc623kplmcqzl4hwxv.png)
opposite angle by the vertex of angle1 is angle3, then
![\angle3=74](https://img.qammunity.org/2023/formulas/mathematics/college/uyl12ugcbwbci15r1u8n68di7qccjdfky6.png)
and angle3 and 7 are the same
![\angle7=74](https://img.qammunity.org/2023/formulas/mathematics/college/n8chauura6m6w1jm1krzbo07tpwz5mtbgj.png)