A question with $x$ and $y$ each defined parametrically in $\theta$ requires you to calculate the slope of the normal to the curve at $\theta$. I've got $\frac{dy}{dx}=\tan\theta$, so the slope of normal is $-\cot\theta= \tan(\frac{\pi}{2}+\theta)$.
Now the answer is that the normal makes an angle of $\frac{\pi}{2}+\theta$ with the $x$-axis, but how is this technically correct? If $\theta$ was $\frac{3\pi}{4}$, for instance, saying that it makes $\frac{5\pi}{4}$ would be incorrect, right? The slope of the normal would be $1$, and it'd make an angle of $\frac{\pi}{4}$ with the $x$-axis, wouldn't it?