137^\circ
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If the angle between the vectors $\mathbf{a}$ and $\mathbf{b}$ is $43^\circ,$ what is the angle between the vectors $-\mathbf{a}$ and $\mathbf{b}$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
137^\circ
If the angle between the vectors $\mathbf{a}$ and $\mathbf{b}$ is $43^\circ,$ what is the angle between the vectors $-\mathbf{a}$ and $\mathbf{b}$?
train