Lesson Plan
Curated OER

Proof of the Pythagorean Theorem Using Transformations

For Teachers 9th - 12th Standards
Middle and high schoolers construct a triangle using Cabri Jr. They construct squares on each of the legs and hypotenuse of the triangle. Pupils show that the area of the squares on the leg equal the area of the square on the hypotenuse.
Worksheet
Math eBook

Centroid of Triangles

For Students 9th - 11th
For this centroid of triangles worksheet, students use given information to determine the centroid of a triangle. They identify the point through which all medians of the triangle pass. This five-page worksheet contains approximately 20...
Lesson Plan
EngageNY

Informal Proof of the Pythagorean Theorem

For Students 8th Standards
Prove the Pythagorean Theorem using multiple informal proofs. Scholars first develop an understanding of the origins of the Pythagorean Theorem through proofs. They round out the lesson plan by using the theorem to find missing side...
Lesson Plan
EngageNY

The Converse of the Pythagorean Theorem

For Teachers 8th Standards
Is it a right triangle or not? Introduce scholars to the converse of the Pythagorean Theorem with a lesson that also provides a proof by contradiction of the converse. Pupils use the converse to determine whether triangles with given...
Worksheet
Curated OER

Review of Trig Ratios

For Students 11th - Higher Ed
In this trigonometric ratios worksheet, students solve and complete 10 various types of problems. First, they write the degrees listed in radian measure. Then, students find the exact ratios for each equation. They also find the value of...
Lesson Plan
Curated OER

Right Triangles

For Teachers 7th - 8th
In this right triangles worksheet, students solve and complete 2 different types of problems. First, they take the case of an isosceles right triangle with a given leg and hypotenuse. Then, students find the sum of the squares of the...
Lesson Plan
EngageNY

Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles

For Students 9th - 10th Standards
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Lesson Plan
Virginia Department of Education

Special Right Triangles and Right Triangle Trigonometry

For Teachers 9th - 11th Standards
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
Lesson Plan
Curated OER

Special Right Triangles

For Teachers 9th - 12th Standards
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
Worksheet
Curated OER

Proofs Of The Pythagorean Theorem?

For Students 8th Standards
Even U.S. President James Garfield had his own proof of the Pythagorean Theorem! Pupils consider three different attempts at a geometric proof of the Pythagorean Theorem. They then select the best proof and write paragraphs detailing...
Handout
Charleston School District

Applications of the Pythagorean Theorem

For Students 8th Standards
Use patterns to your advantage! The Pythagorean Theorem allows learners to find missing sides of right triangles. Problems include those with both rational and irrational lengths. 
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 6th - 7th
For this pythagorean theorem worksheet, students identify the missing length of one side for 10 triangles. Each triangle gives the lengths of two sides and students must find the length of the third. 
Assessment
EngageNY

End-of-Module Assessment Task: Grade 8 Mathematics (Module 7)

For Students 8th Standards
It's time to discover what your classes have learned! The final lesson in the 25-part module is an assessment that covers the Pythagorean Theorem. Application of the theorem includes distance between points, the volume of...
Worksheet
Curated OER

Triangles and Congruence

For Students 8th - 10th
Can your class construct triangles and determine congruence? Find out with this well put together worksheet. THey construct triangles to given specifications and identify if they are congruent. There are 3 muti-step problems to solve.
Worksheet
Curated OER

Area of Right Triangles

For Students 8th - 10th
In this are of right triangles worksheet, students read graphs and explore congruent triangles.  They find the area of rectangles and of right triangles.  This one-page worksheet contains explanations, instructions, and 8...
Worksheet
Curated OER

Triangle Congruence

For Students 8th - Higher Ed
In this triangle congruence worksheet, students review 4 triangle congruence properties and 4 examples. Students are then prompted to complete 15 problems analyzing whether two triangles are congruent and determine by which property.
Lesson Plan
EngageNY

Applications of the Pythagorean Theorem

For Students 8th Standards
Examine the application of the Pythagorean Theorem in problem-solving questions. Pupils apply the theorem to find lengths when given different scenarios. They finish the 17th installment in an 18-part series by applying the theorem...
Interactive
CK-12 Foundation

Related Rates of Car Speeds

For Students 11th - Higher Ed
Speed up your pupils' understanding of derivatives. Two cars travel in perpendicular distances to each other. With the aid of the interactive, learners visualize the situation. Pupils use the derivative to calculate the instantaneous...
Lesson Plan
Curated OER

Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
Lesson Plan
Curated OER

30-60-90 Right Triangles in Cabri Jr.

For Teachers 9th - 12th Standards
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. Students explore the ratios to determine how the hypotenuse...
Lesson Plan
Curated OER

Trigonometric Functions of Acute Right Triangles

For Teachers 9th - 11th
Students derive the six trigonometric functions. In this trigonometry lesson, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig ratios of sine,...
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...
Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...