Answer:
the worker is incorrect
Step-by-step explanation:
Angle DAC measures more than angle BDA
-π/2 < arctan(x) < π/2
So cos(π/2) < cos(arctan(x)) < cos(0)
0 < cos(arctan(x)) < 1
b=16 , First you multiply 30 by 2 to see what sum you need for the numerator. Then you subtract the 60 that you get by the 12 and get 48. So 3 multiplied by b should give you 48. So you just divide 48 by 3 and get 16.