Given that ratio of the angle = 1: 2: 3
Sum of the terms of the ratio – 1 + 2 + 3 = 6
Sum of the angles of a triangle = 1800
∴ 1st angle = 1/6 x 180° = 30° (angle sum property)
∴ 2nd angle = 2/6 x 180° = 60° (angle – sum property)
∴ 3rd angle = 3/6 x 180° = 90° (angle – sum property)
