Texas Instruments
Texas Instruments: Got an Equilateral Triangle? With Cabri Jr.
Using the Compass tool in Cabri Jr., students will construct an equilateral triangle, and check the length of each side. When a vertices is moved using the Alpha hand, the triangle remains equilateral.
Texas Instruments
Texas Instruments: What's the Trig?
Students will be introduced to right triangle trigonometry. They will use the TI-89 and Geometer's Sketchpad to construct a right triangle and calculate sin, cosine, and tangent of various acute angles.
Texas Instruments
Texas Instruments: Triangles
This file contains questions related to triangles. The questions can be used to asses your students' understanding of this topic in geometry.
Texas Instruments
Texas Instruments: Cabri Geometry Tour
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.
Texas Instruments
Texas Instruments: Centers of a Triangle
The centroid, circumcenter, orthocenter, and incenter are the four classic centers of a triangle that are studied in geometry. In this activity, you will construct these center points and discover their properties. [Requires Adobe Reader.]
Texas Instruments
Texas Instruments: Simple Constructions
In this skill activity, students can use the Constructions Tools Menu in Cabri Jr. to contruct a parallelogram. They will also construct an altitude, an angle bisector and a median of a triangle.
Texas Instruments
Texas Instruments: Trig Ratios Exploring Sine, Cosine and Tangent
Using the Cabri Jr. App and the 83+/84+ calculators, students explore and calculate the various trig ratios. This is an easy construction but be sure to allow plenty of time for exploration and completion of the worksheet questions in...
Texas Instruments
Texas Instruments: Measuring Angles in a Triangle
In this activity, students learn about the sum of the angles in a triangle. They understand triangles and their interior angles.
Texas Instruments
Texas Instruments: Triangulation Problem
In this Computer Algebra System (CAS) activity, students use 'landscape' paper and fold the top left corner of the page so that it just touches the bottom of the page. They calculate the area of the triangle formed by the bottom left...
Texas Instruments
Texas Instruments: Exterior Angle Theorem
This activity uses the graphing calculator to show the relationship between an exterior angle of a triangle and the two remote interior angles.
Texas Instruments
Texas Instruments: Angles of a Triangle
In this activity, students will measure angles and investigate the relationships between interior and exterior angles of a triangle. They understand the definition of interior angles, exterior angles, adjacent angles, supplementary...
Texas Instruments
Texas Instruments: Collecting Data in Geometry
This activity is designed for students to make conjectures about triangles. Students will create three lists to represent the measures of the angles of the triangle. The entire class list will then be sent to each student for analysis,...
Texas Instruments
Texas Instruments: Sum of Interior Angles in a Triangle With Cabri Jr.
Students will discover the sum of the interior angles in a triangle using the Cabri Jr. Application.
Texas Instruments
Texas Instruments: Cabri Jr. Side Splitter Theorem
Cabri Jr. activity to study the Side-Splitter Theorem. Page numbers come from Prentice Hall Geometry textbook.
Texas Instruments
Texas Instruments: Measuring Polygons an Introduction to Cabri Jr.
This activity is designed as an introduction to using the Carbri Jr. application on the TI-83+/84+ calculators. Students are guided through the menu system and are shown how to draw triangles, quadrilaterals and and a pentagon. Perimeter...
Texas Instruments
Texas Instruments: Area of Triangle
This Cabri Geometry activity enables students to review the relationship between the height of a triangle and its perimeter and area.
Primary Resources
Primary Resources: 2 D and 3 D Shapes
Here is a huge collection of teacher resources for teaching 2-D and 3-D shapes. Includes smartboard and PowerPoint presentations, as well as worksheets and helpful hints.
Beacon Learning Center
Beacon Learning Center: Congruent or Not?
Students explore congruent polygons in this interactive web lesson.
The Math League
The Math League: Figures and Polygons
This site provides definitions of different types of polygons and figures.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Rectas Notables De Un Triangulo
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.]
CK-12 Foundation
Ck 12: Elem Math: Counting Rectangle,s Squares, Circles, and Triangles in Sets
[Free Registration/Login may be required to access all resource tools.] The video displays a set of figures and reviews triangles by number of sides. Then all of the triangles out of the set of figures are chosen. The video is followed...
CK-12 Foundation
Ck 12: Elem Math: Counting the Number of Different 2 D Shapes in a Set of Figures
[Free Registration/Login may be required to access all resource tools.] The video defines a triangle by the number of sides and then determines which of the figures in the diagram are triangles. The video is followed by additional...
![Pbs Mathline Lesson Plan: Mirror, Mirror [Pdf] Lesson Plan](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "Pbs Mathline Lesson Plan: Mirror, Mirror [Pdf] Lesson Plan")
PBS
Pbs Mathline Lesson Plan: Mirror, Mirror [Pdf]
The goal of this PBS lesson is for students to apply spatial reasoning, problem solving, and critical thinking skills to assess which regular polygons will tessellate. A detailed lesson plan that includes related worksheets, lesson...
PBS
Pbs: Mathline: Tessellations Wow! [Pdf]
An integrated geometry lesson plan on spatial sense in which students identify and use different shapes to create a tessellation. "Through a variety of modalities such as writing, music, art, poetry, and literature, students are...