Height using Reflection from a Mirror
- Azucena Overman
A person places a mirror at point Xm on the ground to look at the building or pole at point C with height h2. You can adjust the height of eye level for the person using the red slider for AB. You can adjust the height of the pole or building by adjusting the red slider for CD. You can move point A to change where the person is standing. You can move point C to change where the building or pole is. You can also move the mirror by moving point Xm. The yellow vectors show the line of site from eye level to the point on the building being reflected. When the top of the building or pole is visible in the mirror the similar triangles are shown.
What do you notice about both green angles for the mirror? What is true about the ratio of height to distance to mirror for both objects when the top can be seen in the mirror? How would you set up a proportion for this problem if the height of the object was not given?