Let the angles be (a – 3d), (a – d), (a + d) and (a + 3d)
a – 3d + a – d + a + d + a + 3d = 360° (sum of angles of quadrilateral)
4a = 360°
a = 90°
According to question,
(a + d) – (a – d) = 10°
2d = 10°
d = 5°
Therefore,
(a – 3d) = 90° – 15° = 75°
(a – d) = 90° – 5° = 85°
(a + d) = 90° + 5° = 95°
(a + 3d) = 90° + 15° = 105°
