Calculating the Height of a Friend's Image from 4.2m Away

[matt72lsu]

Homework Statement

Your friend is 1.7 m tall.

What is the height of her image when she is 4.2 m from you?

Homework Equations

I used di/do and multiplied that by the height of the friend

The Attempt at a Solution

I did (4.2/3.5)(1.7) but it was wrong. Not really sure what I'm doing wrong here.

 

[rl.bhat]

Where the image is formed? On the retina? What is 3.5 in your attempt?

 

[matt72lsu]

nevermind I found my mistake. thanks for the help though