CK-12 Foundation
Ck 12: Trigonometry: Pythagorean Theorem to Classify Triangles
[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to determine if triangles are acute, obtuse, or right triangles.
CK-12 Foundation
Ck 12: Trigonometry: Pythagorean Theorem for Solving Right Triangles
[Free Registration/Login may be required to access all resource tools.] Finding unknown sides in a triangle using other sides and angles.
CK-12 Foundation
Ck 12: Pythagorean Theorem and Pythagorean Triple
[Free Registration/Login Required] Students will determine the number of pixels a phone has on the screen by using the pythagorean theorem and pythaogrean triple. Click learn more to watch a video and click challenge me to answer a...
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
CK-12 Foundation
Ck 12: Algebra: Applications Using the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] In this lesson students use the Pythagorean Theorem to find lengths and distances. Students watch a video tutorial, explore guided notes and attempt practice problems.
CK-12 Foundation
Ck 12: Algebra: Solving Equations Using the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to find a right triangle's missing side lengths.
Wolfram Research
Wolfram Math World: Right Triangle
This site from MathWorld.com offers extensive information on right triangles. The site contains information on numerous characteristics of right triangles, including constructing similar inscribed triangles, altitudes, Pythagorean...
McGraw Hill
Glencoe Mathematics: Online Study Tools: Special Right Triangles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of special right triangles.
Analyze Math
Analyze Math: Area of Triangles
The geometry resource explores the different formulas used to calculate the area of triangles. The applet investigates the angles and sides of a triangle.
Lawrence Hall of Science
The Math Page: Trigonometry: The Isosceles Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of a 45-45-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
Lawrence Hall of Science
The Math Page: Trigonometry: The 30 60 90 Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of the 30-60-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
Purple Math
Purplemath: Basic Trigonometric Ratios: Examples
Demonstrates how to use trig ratios to do simple solving of triangles.
Physics Aviary
Physics Aviary: Triangle Math
Challenges students figure out ten unknown values for right triangles without getting any problems wrong.
CK-12 Foundation
Ck 12: 45 45 90 Triangles
[Free Registration/Login Required] Students use a baseball field to determine the distance between points and 45-45-90 triangles. Click learn more to watch a video and click challenge me to answer a practice question.
Math Warehouse
Math Warehouse: Pythagorean Theorem
Resource takes a look at how to use the Pythagorean Theorem. Includes formulas, examples, animations, and practice problems.
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.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Pythagoras' Theorem
Pythagoras' Theorem: In any right-angled triangle, the square of the length of the hypotenuse (the side that lies opposite the right angle) is equal to the sum of the squares of the other two sides. (A+B=C)
Illustrative Mathematics
Illustrative Mathematics: G C, G Srt Neglecting the Curvature of the Earth
Jerry and Ashley are trying to find out if it is possible to see the lowest point in the USA from the highest point in the USA. It turns out that the highest point in the United States, the peak of Mount Whitney, is only 85 miles from...
Illustrative Mathematics
Illustrative Mathematics: G C, G Srt Setting Up Sprinklers
In this task, learners must decide where to place sprinklers on a lawn so that the maximum area of the lawn will be watered. To solve it, they must find areas of sectors of circles and use trigonometric ratios to solve right triangles....
Illustrative Mathematics
Illustrative Mathematics: G Srt Shortest Line Segment From a Point P to a Line L
In this task, students develop an understanding that the shortest path from a point to a line always meets the line at a right angle. Aligns with G-SRT.C.8.
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg Coins in a Circular Pattern
In this task, students investigate how many coins will fit around a central coin when they are all of the same denomination, and if there is room left over. The teacher is given a chart of four coin denominations and their diameters, but...
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg Seven Circles Iii
For this task, students are shown circle formations where an inner circle is surrounded by a set of circles and all circles are touching. In the first situation, all circles have the same diameter. In the second, the inner circle is...
Illustrative Mathematics
Illustrative Mathematics: G Srt Ask the Pilot
In the July 2013 issue of United Airlines' Hemisphere Magazine, a pilot responded to a question about how far in the distance he could see at different altitudes. The solution involved right triangles, lines of tangency to a circle, and...
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 1
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.