Sorry no computer to draw. You need to visualise.
2nd picture, small unshaded triangle: X + 90 = 112 (ext angle of triangle)
x = 22
Then, open up the fold. You should see X + Y + Y = 90
y = 68/2 = 34
question like this usually needs kids to unfold to see the make up of angles.
ps: Hi Special-One, is this MO question? I see P5 standard SA2 on header of question paper….(?)