Answer:
a=c=30⁰, b=150⁰.
Step-by-step explanation:
angle R is 120⁰ (vertically opposite angle)
so, for vertically opposite angle c we have,
30⁰+120⁰+c=180⁰
Hence, c=30⁰.
angle a = angle c = 30⁰ (corresponding angle).
180⁰-c = b (from figure being straight line)
or, b=180⁰-30⁰
hence, b=150⁰
