Answer
(a) $36cm$ below
(b) $8.9^{\circ}$
(c) You will still see the buckle.
Work Step by Step
(a) We know that the angle of incidence and angle of reflection are equal. Given that the distance between the buckle and eyes is $0.72m$, we conclude that the vertical location of the mirror relative to eyes is $0.36m$ or $36cm$.
(b) We can determine the required angle as follows:
$tan\theta=\frac{Perpendicualr}{Base}$
We plug in the known values to obtain:
$tan \theta=\frac{0.36m}{2.3m}$\
$\implies \theta=tan^{-1}(\frac{0.36m}{2.3m})$
$\theta=8.9^{\circ}$
(c) We know that the person looks at the buckle even if he moves backwards relative to the mirror. The reason behind this is that the triangles made by the incident and reflected light are still similar.
