Well, assuming that lines 'r' and 's' are parallel...
Angle 1 is 50°, this means that Angle 2 must be 180 - 50 = 130°. Because these two angles make up a line, and we know that a line is 180°.
Angle 3 is a corresponding angle to Angle 1, this means it must also equal 50°. Similarly, Angle 4 corresponds to Angle 2, which means it must equal 130°.
Angle 5 corresponds to Angle 1, Angle 5 = 50°
Angle 6 corresponds to Angle 2, Angle 6 = 130°
Angle 7 corresponds to Angle 3, Angle 7 = 50°
Angle 8 corresponds to Angle 4, Angle 8 = 130°