Question

A person wants to see $AB$ part of his image (see Fig.). His eye level is at $1.8m$ above ground. If he uses minimum size of mirror required for this, find the height of lowest point of mirror above the ground.

Answer 1

Figure shows the image of the person and image $A^{\prime }$ and $B^{\prime }$ of points $A$ and $B$, respectively. From the figure,
$h=\frac{1+1.8}{2}=1.4m$.