Insights Blog
-- Browse All Articles --
Physics Articles
Physics Tutorials
Physics Guides
Physics FAQ
Math Articles
Math Tutorials
Math Guides
Math FAQ
Education Articles
Education Guides
Bio/Chem Articles
Technology Guides
Computer Science Tutorials
Forums
Intro Physics Homework Help
Advanced Physics Homework Help
Precalculus Homework Help
Calculus Homework Help
Bio/Chem Homework Help
Engineering Homework Help
Trending
Featured Threads
Log in
Register
What's new
Search
Search
Search titles only
By:
Intro Physics Homework Help
Advanced Physics Homework Help
Precalculus Homework Help
Calculus Homework Help
Bio/Chem Homework Help
Engineering Homework Help
Menu
Log in
Register
Navigation
More options
Contact us
Close Menu
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Forums
Homework Help
Introductory Physics Homework Help
How do similar triangles help determine the visible area in a plane mirror?
Reply to thread
Message
[QUOTE="Wing2015, post: 5001175, member: 541929"] [h2]Homework Statement [/h2] How much of a wall 3m behind you can be observed in a 5 cm square mirror which is held centrally at a distance of 10 cm from your eye? [h2]Homework Equations[/h2] None that I can think of. I think this is straight geometry. [h2]The Attempt at a Solution[/h2] I know I have to use similar triangles but don't understand why. What's the rule of thumb for using similar triangles? Is it because the eye is in common between the wall and mirror? How do I know the two triangles share the same angles? This is the answer in the book: Let the highest part of the wall able to be seen be x metres above the top of the mirror. From similar triangles: X/300 =2.5\10 X=75 cm You can see a square of the wall of length 75+5+75=155cm Now I think I understand why the second similar triangles side length is 2.5cm ( the mirror was placed centrally hence 5cm/2) but can you explain why 75 is added twice and then to the length of the full mirror in the last part? I'm really lost. Any help would be appreciated. Thanks! [/B] [/QUOTE]
Insert quotes…
Post reply
Forums
Homework Help
Introductory Physics Homework Help
How do similar triangles help determine the visible area in a plane mirror?
Back
Top