IM Geo.2.1 Lesson: Congruent Parts, Part 1
What do you notice? What do you wonder?
Triangle ABC is congruent to triangle DEF.
Find a sequence of rigid motions that takes triangle to triangle.
What is the image of segment after that transformation?
Explain how you know those segments are congruent.
Justify that angle is congruent to angle . You can use the applet below.
For each figure, draw additional line segments to divide the figure into 2 congruent polygons. Label any new vertices and identify the corresponding vertices of the congruent polygons.
Use the applet below.
- Draw a triangle.
- Find the midpoint of the longest side of your triangle.
- Rotate your triangle using the midpoint of the longest side as the center of the rotation.
- Label the corresponding parts and mark what must be congruent.
Make a conjecture and justify it.
What type of quadrilateral have you formed?
What is the definition of that quadrilateral type?
Why must the quadrilateral you have fit the definition?