Since opposite angles are the same: angle DEC = 130
We know angle BEC + AED = 360 - 130*2 Since angles in a circle add up to 360 degrees: BEC + AED = 360 - 260 BEC + AED = 100 This means that BEC = 50 and AED = 50
Now that we know 2 angles in the triangle CEB we can work out y: y = 180 - 50 - 70 y = 60 degrees