CTET 2 Math and Science Jul 2019 Paper

Let angle = α
Then, Supplement of angle = 180 – α
Complement of angle = 90 – α
According to question,
Supplement of angle = 4 × Complement of angle
180 – α = 4(90 – α)
180 – α = 360 – 4α
3α = 180
α = 60°