Here, in the above picture given in the question that to find the unknown angles which are 'c' and 'a'.
As, We know that ZR is a straight line. So it makes the linear pair of angles = 180°
- a = 180° - ( 85° + 60° )
- a = 180° - 145° = 35°
So, the angle a = 35°, Now we need to find angle c.
As NT is the transversal line between the two parallel lines of PQ and ZR.
- angle ZNT is alternate interior to the angle c.
- So, ZNT = c = 85°
Hence, The required angle of c is 85°.
