# Homework Help: Images With Plane Mirror

1. Oct 20, 2008

### yayirunin2car

1. The problem statement, all variables and given/known data
The rear window in a car is approximately a rectangle, 1.3 m wide and 0.30 m high. The inside rear-view mirror is 0.62 m from the driver's eyes, and 1.58 m from the rear window. What are the minimum dimensions for the rear-view mirror if the driver is to be able to see the entire width and height of the rear window in the mirror without moving her head?

2. Relevant equations
None really - other than regular geometry stuff like tan theta = y/x, etc.

3. The attempt at a solution
I have none, I've been trying to draw this thing and make triangles or something but I'm completely lost.

Thanks in advance for any help!

2. Oct 20, 2008

### mgb_phys

Forget that it's a mirror and draw the rear window the correct distance in front of the driver, now draw the mirror as a slot restricting the width - how wide does it have to be to get the lines from the driver to the corners of the 'rear' mirror?

3. Oct 20, 2008

### yayirunin2car

Yes! Thank you, :-).