Answer: B
Step-by-step explanation:
3/4 x 4/4 = 12/16
pi·18.6^2·123°/360° - 1/2·18.6^2·SIN(123°) = 226.3
Sum of all adjacent angles is 180°.
3x + 12 + x = 180
4x + 12 = 180
4x = 168
x = 42°
-----------------------------------------
Answer: x = 42°
-----------------------------------------