For number one
S: supplement.
R: angle1+angle8 =18
#2
S: supplement
R: angle 3+ angle 6=180
For any inscribed quadrilateral, the opposite angles add to 180
(angle PMN) + (angle NOP) = 180
(8x-24) + (4x) = 180
12x-24 = 180
12x-24+24 = 180+24 ..... add 24 to both sides
12x = 204
12x/12 = 204/12 ..... divide both sides by 12
x = 17
angle NOP = 4x
angle NOP = 4*17
<h3>
angle NOP = 68 degrees</h3>
There you go. I just drew it to make it easier than giving coordinates