Lesson Plan
Curated OER

Triangle Island

For Teachers 9th - 12th
Students calculate the altitude of triangles.  In the web based lesson plan, students explore the interior distance from a given point in a polygon to its side.  They compute the sum of these lengths. Students read life...
Lesson Plan
Curated OER

IGD: Perpendicular Bisector

For Teachers 9th - 12th
Students draw perpendicular bisectors.  In this perpendicular bisectors lesson, students identify the perpendicular bisector in a polygon.  They use web tools to create and measure perpendicular bisectors.  Students...
Worksheet
Curated OER

Complementary and Supplementary Angles

For Students 10th
In this complementary and supplementary angles activity, 10th graders solve and complete 23 various types of problems. First, they supply a reason to justify each statement in the given sequences. Then, students find the measure of each...
Worksheet
Curated OER

Points, Lines and Planes

For Students 10th
In this points, lines and planes worksheet, 10th graders solve and complete 9 various types of problems. First, they name the planes that intersect a figure shown. Then, students determine the points that are collinear and coplanar in...
Worksheet
Curated OER

Geometry Proofs

For Students 10th
In this geometry proofs activity, 10th graders solve and complete 6 different problems that include various proofs. First, they prove a triangle has equivalent angles as given. Then, students prove two angles supplementary as described.
Worksheet
Curated OER

Midpoint

For Students 7th
In this midpoint instructional activity, 7th graders solve 30 different problems related to determining the midpoint in a series of numbers. First, they identify and construct basic elements of various geometric figures. Then, students...
Worksheet
Curated OER

Naming Angles 2

For Students 10th
In this naming angles worksheet, 10th graders complete 12 problems that identify and name various types of angles in figures. They name a pair of vertical angles and a linear pair in 8 of the problems. Then, students name a pair of...
Lesson Plan
Ministry of Education and Universities of the Region of Murcia (Spain)

Ministerio De Educacion Y Ciencia: Rectas Notables De Un Triangulo

For Teachers 9th - 10th Standards
In Spanish. Interactive activities dealing with the concept of angle bisector, median and altitude of a triangle. A description of the circumcenter and centroid are given along with a visual representation. [Requires Java.]
Activity
Ministry of Education and Universities of the Region of Murcia (Spain)

Ministerio De Educacion Y Ciencia: Tangencias

For Students 9th - 10th Standards
In Spanish. This interactive unit introduces various geometric concepts which are intended to be tools for solving problems of tangencies between straight lines, circles and points.
eBook
Math Planet

Math Planet: Geometry: More About Triangles

For Students 9th - 10th Standards
Explores triangles and related vocabulary through examples and a video lesson.
Unit Plan
CK-12 Foundation

Ck 12: Congruent Angles and Angle Bisectors

For Students 9th - 10th Standards
[Free Registration/Login Required] Students explore the concept of congruent angles and angle bisectors by navigating through the interactive learning module and then answering questions that go along with the module. Students can also...
Unit Plan
CK-12 Foundation

Ck 12: Congruent Angles and Angle Bisectors

For Students 9th - 10th
[Free Registration/Login Required] Students explore congruent angles and angle bisectors through the interactive learning module and then answering questions that go along with the module. Students can also learn more about the concept...
Unit Plan
CK-12 Foundation

Ck 12: Volume of Pyramids: Midpoints and Segment Bisectors

For Students 6th - 9th Standards
[Free Registration/Login Required] Students explore the concept of midpoints and segment bisectors by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn...
Unit Plan
CK-12 Foundation

Ck 12: Volume of Pyramids: Midpoint Map

For Students 9th - 10th Standards
[Free Registration/Login Required] Students explore the concept of midpoints and segment bisectors by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn...
Handout
Wolfram Research

Wolfram Math World: Angle Bisector

For Students 9th - 10th
MathWorld offers a definition for an interior angle bisector accompanied by an example this site also gives a formula for the lenght of the bisector of a triangle.
Handout
Math Open Reference

Math Open Reference: Points and Lines

For Students 9th - 10th Standards
A complete reference guide to points, lines, and planes. It provides definitions and interactive activities that enhance further explanation.
Activity
Other

Gobierno De Navarra: Puntos Y Rectas Notables De Un Triangle

For Students 9th - 10th Standards
Learn how to construct the bisectors, median and altitude of a triangle.
Handout
CK-12 Foundation

Ck 12: Geometry: Bisectors, Medians, Altitudes Study Guide

For Students 9th - 10th
This study guide on bisectors, medians, and altitudes covers key vocabulary, different theorems, and facts about the altitude and triangles. It is available for download with free registration.
Handout
Math Is Fun

Math Is Fun: Definition of Bisector

For Students 3rd - 5th Standards
A clear definition and drawing of a bisector, a line that divides one angle into two.
Handout
The Math League

The Math League: Angles and Angle Terms: Angle Bisector

For Students 9th - 10th Standards
A tutorial on angles with definitions, examples, and pictures.
Handout
Sonoma State University

Sonoma State University: Angle Bisector

For Students 9th - 10th Standards
This site offers an explanation with words and pictures on how to bisect an angle using a compass and straightedge.
Activity
Math Words

Angle Bisector

For Students 9th - 10th
Mathwords provides a brief definition and diagram of an angle bisector.
Handout
Math Open Reference

Math Open Reference: Midpoint of a Line Segment

For Students 9th - 10th Standards
Learn about the midpoint of a line segment with this helpful reference tool. Provides a detailed definition and an interactive activity that enhance further explanation. Includes links to related topics.