Answer:
The answer is 18
Step-by-step explanation:
x+4=2x+1
-x -x
4=x+1
-1
3=x
3+4 = 7
2(3)+1 = 7
7+7=14
BC = 14
(x - 10) + (x - 11) + ( 3x + 6) = 180
5x -15 = 180
5x = 195
x = 39
y = 3x + 6
y = 3(39) + 6
y = 117 + 6
y = 123°