Explanation: A straight line is always 180 degrees, they gave us 160 degrees so you just subtract 180-160 to get 20 degrees for angle 3.
Since that angle is a part of the triangle and we’re only focusing on angles 1 and 2, subtract 20 from 180 since a triangle is 180 degrees.
Then you get 160, divide that by 4 to get 40 degrees, multiply 40 by 3 to get angle 1 which is 120. 120+20 (20 from angle 3) gives us 140. 180-140 is 40 degrees which is angle 2.
