Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Circumcenter of a Triangle

For Teachers 9th - 10th Standards
The goal of this task is to construct the circumcenter of a triangle, that is, the point which is the same distance from each of the triangle's three vertices. This task shows that the three perpendicular bisectors of the sides of a...
Graphic
Curated OER

Perpendicular Bisectors

For Students 9th - 10th
Mathworld's definition of a perpendicular bisector, with illustrations to show the different uses of the perpendicular bisector.
Handout
Math Open Reference

Math Open Reference: Line Segment Bisector

For Students 9th - 10th Standards
Learn about line segment bisectors with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Handout
Oswego City School District

Regents Exam Prep Center: Geometry Vocabulary Resources

For Students 9th - 10th
A list of geometry definitions and a matching activity.
Activity
BBC

Bbc: Ks3 Bitesize: Constructions and Locus

For Students 9th - 10th
This BBC Bitesize focuses on constructions and locus. To understand this activity, you must already know how to define perpendicular, bisect, and locus.
Activity
Texas Instruments

Texas Instruments: Triangle Properties Assessment

For Teachers 9th - 10th
This activity uses Cabri Jr. to assess the students' knowledge of various segments related to triangles: perpendicular bisector, median, angle bisector, midsegment, and altitude.