# Rear view mirror and field of view

A bus driver looks into a plane mirror 20 cm long which is placed 50 cm in front of him. If the rear window is 500 cm from the plane mirror, through what length of the rear window can he see whenever he looks into the mirror while driving?

I have thought about this question but am really stucked. I don't know where to begin the question or how to..

mgb_phys
Homework Helper

Draw a (scaled) diagram, it's all about what range of angles can hit the mirror - just a question of similair triangles

is there no other way such as calculating it?

mgb_phys
Homework Helper

You can calculate it once you understand the layout - thats where the diagram helps

In short, i have to draw the diagram..

Hello Punch,

While it may be possible to for some of us to visualise this problem mentally, you have said that you are finding it very difficult.

Even a rough drawing should help you to understand it better, and a more accurate scaled drawing would also let you make an approximate check on your calculation.