CK-12 Foundation
Ck 12: Geometry: 30 60 90 Right Triangles
[Free Registration/Login may be required to access all resource tools.] Apply the special properties of 30-60-90 right triangles.
CK-12 Foundation
Ck 12: Geometry: 30 60 90 Right Triangles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students about the 30-60-90 special right triangle and how to apply its properties.
Calculator Soup
Calculator Soup: Right Triangles Calculator
Use this calculator to find the unknown angles in a right triangle using the Pythagorean Theorem. Once you know the sides you can calculate the perimeter, semiperimeter, area, and the altitudes.
TeachEngineering
Teach Engineering: Stay in Shape
In this activity, students will learn that math is important in navigation and engineering. Ancient land and sea navigators started with the most basic of navigation equations (Speed x Time = Distance). Today, navigational satellites use...
Oswego City School District
Regents Exam Prep Center: Mean Proportional in a Right Triangle
Material to supplement classroom instruction on mean proportional in a right triangle: a lesson with a definition of "mean proportional" as well as theorems with examples; an online multiple-choice quiz with answers; and guidelines for...
Other
Achieve: Miniature Golf Design Task [Pdf]
In this task students are asked to combine numerous skills to create a miniature golf hole. Students create a scale drawing of the hole, calculate the area of the hole and determine the percentage of total area used. In addition,...
CK-12 Foundation
Ck 12: Distance Formula
[Free Registration/Login Required] Students explore the concept of the distance formula by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...
CK-12 Foundation
Ck 12: Volume of Pyramids: Biking the Blocks
[Free Registration/Login Required] Students explore the concept of distance between two points by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more...
Cool Math
Coolmath: Precalculus Basic Formulas to Know
This CoolMath resource provides an introduction to some Precalculus formulas.
Illustrative Mathematics
Illustrative Mathematics: 8.g, G Gpe, G Srt, G Co Is This a Rectangle?
For this task, students are given four sets of coordinate pairs and are asked to determine if they represent a rectangle. Aligns with 8.G.A, 8.G.B, G-CO.B, G-GPE.B, and G-SRT.B.5.
Other
New York State Education Department: Eighth Grade Math, Book Two (2010) [Pdf]
Part two of three; The March 2010 8th grade Math test from the State of New York. The test is six open-response questions covering topics such as geometry (intersecting / parallel lines, Pythagorean Theorem), measurement (maps), and...
Khan Academy
Khan Academy: Distance Formula
Review how to derive a general formula for the distance between two points.
National Council of Teachers of Mathematics
The Math Forum: Famous Problems in the History of Mathematics
On this site, there are several math problems to explore and solve. Look through some solutions by famous mathematicians and expand your thinking about some interesting math concepts. Teachers of elementary grades may want to use this...
Illustrative Mathematics
Illustrative Mathematics: G Co Inscribing a Square in a Circle
In this lesson, students learn how to inscribe a square in a circle. Aligns with G-CO.D.13
That Quiz
That Quiz
ThatQuiz is an excellent assessment tool for teachers and students. At this site, teachers can create individualized or group assessments on a variety of math topics. Students take these practice assessments directly online and receive...
Alabama Learning Exchange
Alex: How Tall Is the School's Flagpole?
The purpose of this lesson plan is to help students apply math concepts concerning similar triangles and trigonometric functions to real life situations. The students learn how to take these concepts and use them to find measurements of...
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?"...
University of Georgia
University of Georgia: Inter Math: Recommended Investigations of the Triangle
Investigate the qualities of a triangle with these seventeen word problems. Many include ways to extend the lesson.
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
National Council of Teachers of Mathematics
The Math Forum: The Volume of a Pyramid
This question and answer site from the Math Forum with Dr. Math presents a problem dealing with the volume of a pyramid. Links are also provided for additional information on related subjects.
Cut the Knot
Cut the Knot!: Example of Convergent Infinite Series
This site explains the sum of a simple convergent series using a geometric illustration.
Cut the Knot
Cut the Knot!: The Law of Cosines (Cosine Rule)
This site from Cut The Knot provides an overview of the law of cosines, complete with an explanation of the law and a proof of the law.
Other
Ctte: Geometer's Sketch Pad Activities
This site offers numerous activities for middle school and high school learners to explore using Geometer's Sketch Pad.