The angle of 110° and the angle labelled as 1 form 180°, so we have
![<1> = 180-110=70](https://img.qammunity.org/2020/formulas/mathematics/middle-school/r1w1eufq9886p536iiiwra5chpd2moc0xh.png)
The same holds for the angle labelled 2 and the 115° angle:
![<2> = 180-115=65](https://img.qammunity.org/2020/formulas/mathematics/middle-school/muissxvwgjrzh1wip0uwzq8ooj34plh65k.png)
Angle 1, 2 and 7 are the interior angles of a triangle, so they sum to 180. We can deduce
![<7> = 180-70-65=45](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3s0dlbjnaj6s4xyow6x1ljnp1fh8t0pfd8.png)
Angles 5 and 7 are corresponding angles, so they have the same measure.