+
Lesson Plan
Curated OER

When Does SSA Work to Determine Triangle Congruence?

For Teachers 9th - 10th Standards
Your learners will make good use of the Socratic method in a collaborative task that begins with an assumed solution and ends with deeper understanding of the idea of determining two triangles congruent.
+
Printables
Readington Township Public Schools

Facts Practice Using Multiplication/Division Fact Triangles

For Teachers 3rd - 5th Standards
Why waste time teaching multiplication and division facts separately, when this resource allows you to cover both concepts at once. Displaying the fact families for all single-digit factors, these triangle shaped flash cards are a great...
+
Interactive
CK-12 Foundation

Special Triangle Ratios: Special Right Triangle Ratios

For Students 9th - 12th Standards
Go from one side length to any other side length with special right triangles. Individuals use the interactive to investigate the ratio of sides in 45-45 and 30-60 right triangles. Scholars make generalizations about the types of special...
+
Worksheet
Curated OER

Similar Triangles and Trapezoids, and Circles

For Students 9th - 12th
High schoolers answer two problems involving area of shaded regions. Students then answers six questions involving perimeter, area, and circumferences. The remaining two questions involve ratios of similar figures.
+
Instructional Video10:02
2
2
Flipped Math

Special Right Triangles II

For Students 9th - 12th
Show students that right triangles are radical. Learners see how the lengths of the sides of a 45-45-90 triangle relate. Using that relationship, pupils observe how to find any of the lengths given one side of a triangle. They go on to...
+
Interactive
CK-12 Foundation

Determination of Unknown Triangle Measures Given Area: Jib Sheets

For Students 10th - 12th Standards
Solving triangles is a breeze. Young boat enthusiasts solve problems involving triangles in the context of sails on a boat. They must apply different strategies, including the Law of Cosines and area formulas.
+
Unit Plan
Radford University

Right Triangle Sports

For Teachers 9th - 12th Standards
Who knew math could help with sports? An invigorating set of lessons encourages learners to apply right triangles in baseball, volleyball, hockey, football, and soccer. They use the Pythagorean Theorem, Pythagorean triples, special right...
+
Lesson Plan
West Contra Costa Unified School District

Dilations Using Right Triangles

For Teachers 9th - 12th Standards
Don't argue with a triangle that has a 90-degree angle. It's always right. Scholars first use right triangles to help draw dilations of points. They continue the instructional activity by applying this skill to draw dilations of polygons.
+
Performance
Radford University

Triangles in Parallelograms

For Teachers 9th - 12th Standards
What's the point of looking at triangles when trying to draw parallelograms? Given three non-collinear points, pupils determine and justify all possible points that would create a parallelogram. They then analyze the four triangles that...
+
Instructional Video7:06
2
2
Flipped Math

Unit 7 Review: Right Triangles

For Students 9th - 12th Standards
It is all right to spend some time with a review. After watching a short review video covering the materials from the unit, pupils work through 23 review problems. Scholars work on problems involving the Pythagorean Theorem and its...
+
Interactive
CK-12 Foundation

Right Triangles, Bearings, and Other Applications: Sailing Race

For Students 9th - 12th Standards
Help your class get their bearings when it comes to right triangles. Pupils determine distances traveled or components given the bearing of a sailboat using an interactive. The scholars develop a sense of finding the bearings of a given...
+
Interactive
CK-12 Foundation

Distance Formula: Right Triangles

For Students 8th - 10th Standards
Go the distance with a far out resource. Individuals use an interactive to create right triangles on a coordinate plane to help find distance between two points. Challenge questions aid them in developing the distance formula.
+
Interactive
CK-12 Foundation

Angle-Angle-Side Triangles: Garden Gate

For Students 10th - 12th Standards
Good fences make good gardens. Individuals use an interactive to see how angles and sides relate in a triangular-shaped garden fence. They apply the Law of Sines to find the length of the garden gate (third side of triangle) given two...
+
Interactive
CK-12 Foundation

Possible Triangles with Side-Side-Angle

For Students 10th - 12th
It's not often that math allows for multiple answers. Young mathematicians identify possible numbers of triangles when given two sides and a non-included angle. An interactive helps with this investigation.
+
Instructional Video16:10
2
2
Flipped Math

Parallelograms and Triangles

For Students 9th - 12th Standards
Expand area problems to incorporate prior knowledge. Pupils begin by reviewing the formulas for finding the area of parallelograms and triangles. The scholars apply previous learning of trigonometric ratios and the Pythagorean Theorem to...
+
Lesson Plan
Curated OER

Triangles

For Teachers 6th - 10th
Students identify triangles in the real world and construct their own triangle using drinking straws. They explore abstract triangles and find additional geometric shapes such as trapezoids. Students discuss similar shapes and examine...
+
Worksheet
Curated OER

Perimeter of Triangle Worksheet

For Students 7th - 8th
In this perimeter worksheet, students find the perimeter of given triangles.  This two-page worksheet contains 6 problems.  Answers are provided on the last page.
+
Assessment
Mathed Up!

Sine and Cosine Rules and Area of Triangles

For Students 9th - 12th
Learners discover how to find missing sides and angles using trigonometry. Scholars first watch a video covering the Law of Sines and Cosines, as well as the area formula for a triangle. To test their knowledge, they complete a worksheet...
+
Lesson Plan
EngageNY

Incredibly Useful Ratios

For Students 9th - 10th Standards
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent sides before exploring...
+
Assessment
Concord Consortium

Always, Sometimes, Never

For Students 9th - 10th Standards
Do your learners always, sometimes, or never remember the properties of the segments in triangles? Get that number closer to always with a creative lesson analyzing all four segments. Scholars consider a statement about one of the...
+
Lesson Plan
EngageNY

Prove the Pythagorean Theorem Using Similarity

For Students 9th - 10th Standards
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
+
Lesson Plan
EngageNY

Pythagorean Theorem, Revisited

For Students 8th Standards
Transform your pupils into mathematicians as they learn to prove the popular Pythagorean Theorem. The 16th lesson in the series of 25 continues by teaching learners how to develop a proof. It shows how to prove the Pythagorean Theorem...
+
Lesson Plan
EngageNY

Informal Proof of AA Criterion for Similarity

For Teachers 8th Standards
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
+
Worksheet
Math Wire

How Many Winter Paths Do You See?

For Teachers 6th - 8th
Is the path through December, January, and February the only path through winter? Not in a holiday math activity based on Pascal's Triangle! Middle schoolers study a triangle made of the letters from the word winter and decide how many...

Other popular searches