Unit Plan
Oswego City School District

Regents Exam Prep Center: Geometric Constructions

For Students 9th - 10th Standards
Learn all about the basic geometric constructions in this test prep lesson. You will explore line segments and points, and understand key terms like the terms parallel and perpendicular. Construction activities and interactive online...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Angle Bisection and Midpoints of Line Segments

For Teachers 9th - 10th Standards
This task provides a construction of the angle bisector of an angle by reducing it to the bisection of an angle to finding the midpoint of a line segment. Aligns with G-CO.D.12.
Activity
Other

Advogato: Trigonometry by Geometric Construction

For Students 9th - 10th Standards
This site from Advogato is all about angles. It contains information starting with what an angle is and what it looks like, all the way up to bisecting angles and theorems about angles. This is very good information for students just...
Activity
Oswego City School District

Regents Exam Prep Center: Copy a Line Segment and an Angle

For Students 3rd - 8th Standards
This site provides a step-by-step method to construct congruent segments and angles with a straight edge and compass.
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 5.3 Parallel and Perpendicular Line Constructions

For Students 9th - 10th Standards
Understand the step-by-step processes used to create accurate geometric figures.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Construction of Perpendicular Bisector

For Teachers 9th - 10th Standards
A and B are two distinct points in the plane and line AB is the segment joining them. The goal of this problem is to construct the perpendicular bisector of segment AB. Aligns with G-CO.D.12.
Lesson Plan
National Council of Teachers of Mathematics

The Math Forum: Geoboard Activities

For Teachers 9th - 10th Standards
Math Forum provides a set of links to sites that are related to geoboard activities. There are several great links to lessons using geoboards. The links provide insight into how to use them, including how to perform various measurements...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Points Equidistant From Two Points in the Plane

For Teachers 9th - 10th Standards
In this task, students are shown a line segment that is bisected at a right angle by a second line. They are asked to prove statements about this geometric construction. Includes a GeoGebra worksheet that can be used by the instructor to...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Reflected Triangles

For Teachers 9th - 10th Standards
In this task, students must use a straightedge and compass to construct the line across which one triangle was reflected onto another. Aligns with G-CO.A.5 and G-CO.D.12.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Origami Equilateral Triangle

For Teachers 9th - 10th Standards
The purpose of this task is to explore reflections in the context of paper folding. Each fold is associated with a line of reflection and understanding each step in the construction requires careful analysis of angles and of the...
Website
Other

Antonio Gutierrez: Geometry From the Land of the Incas

For Students 9th - 10th
Discovering the properties of constructions, seeing proofs in action, and viewing problems come to life here with this wonderful use of technology in the classroom. Single steps are explained and illustrated one at a time so that the...
Activity
Texas Instruments

Texas Instruments: Cabri Geometry Tour

For Teachers 9th - 10th Standards
In this activity, students use the Cabri software to mark points, draw lines, construct parallel and perpendicular lines, angles, bisectors, and triangles. They learn how to use the tool to measure angles.
Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Triangle Formulas

For Students 9th - 10th
Investigate the geometric definitions of triangles, focusing upon equilateral, isosceles, right, and scalene with detailed drawings and appropriate formulas for each. This site has links to more information on triangles.
Website
Wolfram Research

Wolfram Math World: Geometry

For Students 9th - 10th
This MathWorld tutorial provides detailed overviews of the concepts and theorems associated with geometry. Most of the Math World sites are extensive and some require higher math knowledge to understand, links to terms and topics are...
Activity
Ministry of Education and Employment of Spain

Red Escolar: Un Triangulo Sorprendente

For Students 9th - 10th Standards
In Spanish. Different activities which involve the following concepts: right triangles, perpendicular lines, classification of triangles, area of a square and Pythagorean theorem.
Lesson Plan
Other

Ctte: Geometer's Sketch Pad Activities

For Teachers 9th - 10th
This site offers numerous activities for middle school and high school students to explore using Geometer's Sketch Pad.