Angle CBE is 50 because 40+90=130 so 180-130=50
If you are wondering where I got 90 from, well angle CEB is a right angle so that’s 90.
If you are wondering where I got 180 from, well a triangle adds up to 180.
Sorry, this is all I know but I hope some of this helped, have a good day, and good luck finding out the other 2 angles.