X - the score he must get

He must get at least 92 points.
Is this simultaneous equations?
if yes then the first step is
make one of the unknown as the subject
The figure is shown below
From the figure
Angle 150 degree and angle p forms angles on a straight
Since the sum of angles on a straight line equals 180 degrees
Hence

Solve for p in the equation

Hence, p = 30
From the figure
Angle p and angle q are vertically opposite angles
Since vertically opposite angles are equal then

Hence, q = 30
Applying the rule of angles on a straight line
This implies

Substitute q = 30 into the equation

Solve for w

Hence, w = 90
Answer:
62.8 in
Step-by-step explanation:
Circumfrence=pi x diameter
3.14 x 20=62.8