Answer:
Angles B & C both = 157 degrees . 
Explanation:
Angle A is adjacent to Angle B, which means they are the same size. 23 degrees for A & B. 
23+23 = 46. 
We have two straight lines, one line = 180. 180*2 = 360. 
Take 46 from 360 because we already figured out two angles. 
360 - 46 = 314 
Divide 314 by 2 because we have two unknown angles... 
314 / 2 = 157 . 
Angle B & C = 157.