posted by shan .
You are 1.7m tall and your eyes are 8cm from the top of your head. How tall must a vertical plane mirror be to see your entire length? Also how far from the ground is the top of the mirror?
Have you considered drawing a figure with a mirror, then drawing ray diagrams? On ray from the foot to the mirror to eye, and one ray from top of head to mirror to eye. Then use geometry to figure the height of the mirror.