We know all these angles combined equals 360, so:
3x + 20 + 3x + 20 + x + x = 360
8x + 40 = 360
8x = 320
x = 40
Hope this helps!
Fourths, (1/4), (.25), (25%)
The grocery store selling a 3 pound bag for $4.20. while the other store would sell it for $4.50.