BBC
Bbc: Bitesize: Math: Angles
What is an angle? Read about and see examples of the three different types while learning how to use a protractor. Links to an online game and an interactive quiz.
Math Is Fun
Math Is Fun: Finding an Angle in a Right Angled Triangle
Students learn how to find an angle of a right triangle. The tutorial consists of notes, examples, and practice problems to check for comprehension.
Math Is Fun
Math Is Fun: Sohcahtoa: Sine, Cosine, Tangent
Students learn about the relationships between sine, consine, and tangent. The tutorial consists of notes, examples, and practice problems to check for comprehension.
Texas Instruments
Texas Instruments: Similar Triangles and Proportions
In this activity, students will investigate the relationship among the similar triangles formed when a segment is constructed parallel to one side of a triangle. They will explore the various ratios that exist between the lengths of the...
Mangahigh
Mangahigh: Shape: Opposite Angles
Explore opposite angles by chosing the appropriate angle for the missing degree of measure.
CK-12 Foundation
Ck 12: Triangle Classification
[Free Registration/Login Required] Students will move the vertices to different points to create different obtuse triangles. Click learn more to watch a video demonstration and click challenge me to answer a practice question.
Analyze Math
Analyze Math: Cosine Law Problems
Here are four problems to solve using the Law of Cosines. Two are SSS problems; two are SAS problems. Two have detailed solutions; two have answers given only. Notice the link at the bottom that takes you to a Law of Cosines calculator -...
Analyze Math
Analyze Math: Triangle Problems
Here are five triangle problems to solve using the Law of Sines, Law of Cosines, Pythagorean Theorem, and trigonometry. All problems have detailed written solutions included.
Analyze Math
Analyze Math: Angles in Geometry
Definitions and properties of angles in geometry are explored. Topics discussed are right, acute, and complementary angles. Practice exercises with solutions are included.
Analyze Math
Analyze Math: Inscribed and Central Angles in Circles
The geometry tutorial investigates the definitions and theorems related to inscribed and central angles in circles. An example with a detailed solution is included.
University of California
University of California: Triangles and Simplices
This site from the University of California deals with different applications and topics pertaining to triangles, particularly triangulation.
Lawrence Hall of Science
The Math Page: Trigonometry: Solve Right Triangles
Here is a site that clearly and thoroughly explains how to solve right triangles for any missing side or angle given any two pieces other sides or angles. There are example problems solved, problems for the student to attempt, and...
Lawrence Hall of Science
The Math Page: Trigonometry: The Law of Sines
Work through an explanation of the law of sines, how it is used with an obtuse angle, and a proof of the law of sines. Great site for students studying trigonometry.
Math Planet
Math Planet: Geometry: Angles, Parallel Lines and Transversals
Angles, parallel lines, and transversals are explained through examples and a video lesson. [1:01]
Math Planet
Math Planet: Pre Algebra: Angles and Parallel Lines
Explains angles and parallel lines through examples and a video lesson.
Math Planet
Math Planet: Pre Algebra: Triangles
Learn about the types of triangles by taking a look at an example and a video lesson.
Math Planet
Math Planet: Geometry: Parallelogram, Triangles Etc
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
Cool Math
Coolmath: Geometry & Trig Reference
Math formulas, definitions, properties, diagrams and examples from Geometry and Trigonometry.
Khan Academy
Khan Academy: Solve for an Angle in Right Triangles
Given two sides in a right triangle, find one of the acute angles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Lawrence Hall of Science
The Math Page: Trigonometry
Concepts in Trigonometry are explained and illustrated here by a member of the math department at Borough of Manhattan Community College.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Triangles Congruence
This lesson focuses on triangle congruence; it shows the ways to prove that triangles are congruent.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Applications
This lesson focuses on the real world applications using triangles and trigonometry.
Illustrative Mathematics
Illustrative Mathematics: F Tf Equilateral Triangles and Trigonometric Functions
The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.
Khan Academy
Khan Academy: Trigonometric Ratios in Right Triangles
Given the side lengths of a right triangle, find the sine, cosine, or tangent of one of the acute angles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.