Cuemath
Cuemath: Law of Cosine
Explore the world of the Law of Cosine in this mini-lesson. Provides a definition, simulations, examples, and practice questions that help with understanding.
Cuemath
Cuemath: Acute Triangle
Explore the world of acute triangles in this mini-lesson. Explores its properties, how to create it, and other interesting facts related to acute triangles.
Cuemath
Cuemath: Sine Law
This comprehensive guide explores the topic of sine law, by finding answers to questions like what is the law of sines, what are the applications of sine law, and proof of the sine law. Includes solved examples and practice questions.
Curated OER
Zona Land: Trigonometry, Right Triangles
This site provides information on sine, cosine, and tangent. Lengths of the sides are discussed and many diagrams/tables are shown.
Government of Alberta
Learn alberta.ca: Mathematics Glossary: Adjacent Angles
LearnAlberta.ca's Mathematics Glossary defines adjacent angles and gives several examples to illustrate the concept. [Requires Java.]
Windstream
Ojk's Precalculus Study Page: The Law of Cosines
An introduction to solving acute and obtuse triangles by using the law of cosines, including a derivation of the formula. Includes several pistures and examples.
Wolfram Research
Wolfram Math World: Law of Cosines
This page from MathWorld.com gives a good explanation of the Law of Cosines, which relates the lengths of the legs of a triangle to the angles. This site shows how the formula is derived, along with a triangle to clarify variables. Also...
Texas Instruments
Texas Instruments: Constructing Triangles
This activity focuses on the various ways to construct the different types of triangles such as isosceles, equilateral, right, and right isosceles triangles. Students will begin by constructing triangles based on a minimal definition of...
Texas Instruments
Texas Instruments: Angle Sum in Triangles Proof: Rotation and a Parallel Line
This investigation uses Cabri Jr. and a cleaver rotation of a triangle to "prove" that the angles in a triangle add up to 180. This could be used to reinforce triangles and paralled lines as well as introduce the concept of rotating an...
Texas Instruments
Texas Instruments: Math Today When a Ruler Isn't Enough
This activity illustrates a real-life problem that uses trigonometry to solve for an unknown. students can use trigonometric ratios and inverse trigonometric relationships to determine the side of a triangle and the measure of the...
Texas Instruments
Texas Instruments: Sin, Cos, and Tan of Right Triangles
In this activity, students explore a right angled triangle and its trigonometric concepts. They investigate the trigonometric ratios for the angles of the triangle.
Texas Instruments
Texas Instruments: Central Versus Inscribed Angles in Circles
Using Cabri Jr. to explore the connection between central and inscribed angles along with their arc measure.
Texas Instruments
Texas Instruments: Angles in Circles
The student will use the Cabri Jr. APP to discover the relationship between inscribed and central angles in a circle.
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: Ratios in Right Triangles
The study of properties of right triangles is a major topic in mathematics. In this activity, you will investigate three common right triangle trigonometric ratios. [Requires Adobe Reader.]
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: What's the Angle?
Students discover properties of interior and exterior angles of convex polygons using the TI-89 and Geometer's Sketchpad.
Texas Instruments
Texas Instruments: Mc Dougal Littell Geometry: Investigate Proportionality
Students can use the TI-84 Plus family with Cabri Jr. to segment lengths in a triangle.
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: Angle Theorem
Students use the Cabri Geometry II Plus software to investigate the relationship between angle and ratio in a right triangle.
Texas Instruments
Texas Instruments: Right Triangle Trig
This is a way to use the TI-Navigator to check for an understanding of sin, cos, and tan before you move onto word problems.
Texas Instruments
Texas Instruments: Opposite Angles in a Cyclic Quadrilateral
This activity uses Cabri Jr. to discover that opposite angles in a cyclic quadrilateral are supplementary
Texas Instruments
Texas Instruments: Copying an Angle
Explore relationships (including congruence and similarity) among classes of two- and three-dimensional geometric objects, make and test conjectures about them, and solve problems involving them.