A full turn around a point equals 360º. If a full turn equals 360º, then the sum of the angles around a point must also be 360º. When you calculate angles around a point, you can use this fact to find ...

\(x\) is 50°. Corresponding angles are equal. \(y\) is 180° - 50° = 130°. Angles on a straight line add up to 180°.