Geometry Help
Geometry Help: Pythagorean Theorem
Explains the basic concept of the Pythagorean Theorem with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Math Open Reference
Math Open Reference: 45 45 90 Triangle
Explore the triangle inequality theorem with this helpful reference tool. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
Khan Academy
Khan Academy: Reciprocal Trig Ratios
Understand the right triangle definition of sec, csc, and cot ratios.
CK-12 Foundation
Ck 12: Algebra Ii: 4.2 Right Triangle Trig Extended to Circles With a Model
This section explores the relationship between right triangles, circles, and trigonometry. It investigates how a right triangle that is set inside a circle and rotates around the circle is connected to trigonometric functions and their...
CK-12 Foundation
Ck 12: Algebra Ii: 4.1 Revisiting Right Triangle Trigonometry
Use this tutorial to revisit right triangle trigonometry.
CK-12 Foundation
Ck 12: Algebra Ii: 4.8 Pythagorean Identities
This section explores the Pythagorean Identity and how it applies to right triangles set inside unit circles, in terms of sine, cosine, and tangent functions.
OER Commons
Oer Commons: Pre Assessment
Students solve for missing angle measures by applying what they have learned about types of angles and the angle measures of polygons. Students do a pre-assessment at the end of the lesson.
OER Commons
Oer Commons: Classifying Triangles
In this lesson, young scholars learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included...
CK-12 Foundation
Ck 12: Interactive Geometry: 17.4 Inverse Trigonometric Ratios
Define the trigonometric ratios in terms of ratios of the sides of a right triangle.
CK-12 Foundation
Ck 12: Interactive Geometry: 17.1 Tangent Ratio
Explore and understand tangent ratios.
Khan Academy
Khan Academy: Right Triangle Word Problems
Solve word problems by modeling real-world (and not-so-real) situations as right triangles and using trigonometry.
Purple Math
Purplemath: The Pythagorean Theorem
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Purple Math
Purplemath: Inverses of Trigonometric Ratios
You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...
Purple Math
Purplemath: Right Triangle Word Problems
Demonstrates how to translate, set up, and solve basic right-triangle word problems.
E-learning for Kids
E Learning for Kids: Math: Riksjas, Toek Toek: Polygons
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!
Math2
Math2.org: Trigonometry Functions
A complete look at trig functions. From an "overview," page giving general definitions and important vocab words, to a listing of the 12 trig functions, to an explanation of the three modes used in trigonometry, to the procedures of how...
Pennsylvania State University
Pennsylvania State Univ.: Trilingual Packaging Dilemma
This site from the Pennsylvania State University provides a hands-on activity to bridge the gap between right triangles, 30-60-90 and 45-45-90 theorems, and trigonometry, and what every student wants to know, "When will I ever use this?"...
The Math League
The Math League: Figures and Polygons
This website has basic definitions for most polygons, regular and irregular.
Doina Popovici
Math Play: Pythagorean Theorem Jeopardy Game
This jeopardy-style game will have students calculate the sides of a right triangle by using the Pythagorean Theorem.
Doina Popovici
Math Play: Classifying Triangles
Practice identifying triangles as either acute, right, or obtuse in this interactive game.
Other
Ic Teachers: Shapes: Triangles
Are you looking for a very basic website that will explain the basic properties of a triangle? Use this site to learn about the properties of equilateral triangles, isosceles triangles, right triangles,and scalene triangles. There are...
Mr. Martini's Classroom
Mr. Martini's Classroom: Right Angle Trigonometry
Explore sine, cosine, and tangents compared to the selected angle.
Sophia Learning
Sophia: Triangle Height: Lesson 2
This lesson will demonstrate how to locate the height in an obtuse, right, and acute triangle. It is 2 of 5 in the series titled "Triangle Height."
Sophia Learning
Sophia: Triangle Height: Lesson 4
This lesson will demonstrate how to locate the height in an obtuse, right, and acute triangle. It is 4 of 5 in the series titled "Triangle Height."