What is the smallest a flat mirror can be while still being able to see your full reflection?
I need to show my work/explain. Can anyone help me?
2 answers
draw a ray diagram from the eyes to the feet. Draw a second ray diagram from the eye to the top of the head. Now, use geometry and congruent triangles to solve your question.
Draw the mirror opposite you and parallel to you
Put your eye at the top of your head.
Draw a line from your eye straight to the mirror perpendicular to it. The line bounces right back to your eye, so you have the top of you.
Now draw a line from your eye, bounce off the mirror, and hit your foot.
You will notice the bounce occurs halfway down the mirror. By pretending the mirror has a hole at exactly that point halfway down, you can continue that line from your eye through the mirror through to the floor behind the mirror. Then you can work the geometry out by similar triangles if you wish.
So the mirror only needs to be half your height
Put your eye at the top of your head.
Draw a line from your eye straight to the mirror perpendicular to it. The line bounces right back to your eye, so you have the top of you.
Now draw a line from your eye, bounce off the mirror, and hit your foot.
You will notice the bounce occurs halfway down the mirror. By pretending the mirror has a hole at exactly that point halfway down, you can continue that line from your eye through the mirror through to the floor behind the mirror. Then you can work the geometry out by similar triangles if you wish.
So the mirror only needs to be half your height
1 answer