Given that the angles of the triangle are in ratio 1 : 2 : 3

Let, the angles be a, 2a, 3a

Therefore, we know that

Sum of all angles if triangle is 180^o

a + 2a + 3a = 180^o

6a = 180^o

a =

a = 30^o

Since, a = 30^o

2a = 2 (30^o) = 60^o

3a = 3 (30^o) = 90^o

Therefore, angles are a = 30^o, 2a = 60^o and 3a = 90^o

Hence, angles are 30^o, 60^o and 90^o.