Shape and space question

[rapid ravine]

how do i do thissss help plss

[soft badge]

<OCA = <OBA = 20°
<BOC = 2y = 2z -> y = z
<CBO = <OCB = 90° - z = 90° - y
Triangle ABC:
y + 2 × ((90° - y) + 20°) = 180°
y + 2(90° - y) + 40° = 180°
y + 180° - 2y + 40° = 180°
-y + 40° = 0
y = z = 40°
<CBA = (90° - 40°) + 20° = 70°
x = 180° - 40° - 70° = 70°

[rapid ravine]

okay yea thankyou.. this is the same answer i got but in the text book answer it says x=40,y=70 and z=40