Exploring Reflections with GeoGebra

Reflecting in GeoGebra

Directions: 1. For this warm up, you will need to select the tool that looks like a division symbol from the GeoGebra tool bar below. Once you have selected the tool, click on the object you want to reflect, then the line of reflection. 2. Complete the following reflections:

Reflect Point M across reflection line QR.
Reflect Line AB across reflection line QR.
Reflect Triangle TOP across reflection line QR.

3. After performing these reflections click on the select tool to move the objects and/or the reflection line to investigate properties of a reflection. 4. To conclude the warm up, answer the question about properties of a reflection. 5. Press "Check My Answers" and record your response to the properties of a reflection before returning to the lesson to see what your classmates observed.

Properties of a Reflection

Which of the following properties apply to all reflections? (Choose all that apply)

Select all that apply

A
Distance is preserved. This means lengths between pre-image points are the same as lengths between their images. (In general AB = A'B')
B
Angle measure is preserved. This means angle measures between pre-image points are the same measure as the angles between their images. (In general angle TOP = angle T'O'P')
C
Segments formed by pre-image and matching image are parallel. (In general segment AA' // segment BB')
D
Distances between pre-image and matching images are equal. (In general AA'=BB')
E
The line of reflection is the perpendicular bisector of the segments between each pre-image and image point. (In general QR is perpendicular bisector of segment AA')
F
Orientation is preserved. This means order of points around the pre-image polygon are in the same direction as the image. (In general if TOP is clockwise, so is T'O'P')

Check my answer (3)

Exploring Reflections with GeoGebra

Reflecting in GeoGebra

Properties of a Reflection

New Resources

Discover Resources

Discover Topics