EngageNY
An Area Formula for Triangles
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Illustrative Mathematics
Use Cavalieri’s Principle to Compare Aquarium Volumes
Learners are designing a stunning new water feature for an aquarium, but they soon discover that more than just a pretty home for their fishy friends is required. From calculating the volume of a composite shape through the...
Mathed Up!
Sine and Cosine Rules and Area of Triangles
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...
EngageNY
Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
EngageNY
The Volume Formula of a Sphere
What is the relationship between a hemisphere, a cone, and a cylinder? Using Cavalieri's Principle, the class determines that the sum of the volume of a hemisphere and a cone with the same radius and height equals the volume of a...
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
EngageNY
Getting a Handle on New Transformations 1
In the first of a two-day lesson on transformations with matrix notation the class transforms the unit square using general transformations, then calculates the area of the transformed image. They discover it is the same as finding...
CK-12 Foundation
Volume by Cross Section: Volume of the Cone
Discover another way to find the volume of a cone. Pupils explore how the area of a cross section changes as it moves through a cone. The interactive uses that knowledge to develop the integral to use to find the volume of the cone....
Hotchalk
Triangle Sum Theorem
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
EngageNY
Complex Numbers and Transformations
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
EngageNY
End-of-Module Assessment Task: Grade 8 Mathematics (Module 7)
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...
EngageNY
Integer Sequences—Should You Believe in Patterns?
Help your class discover possible patterns in a sequence of numbers and then write an equation with a lesson that covers sequence notation and function notation. Graphs are used to represent the number patterns.
Curated OER
Shipping Rolled Oats
What better way to start your day than with a box of oatmeal? Or what better way to start your geometry class than by calculating its volume? Eighth graders discover just how practical volume computation can be in business and in breakfast!
EngageNY
When Can We Reverse a Transformation? 1
Wait, let's start over — teach your class how to return to the beginning. The first lesson looking at inverse matrices introduces the concept of being able to undo a matrix transformation. Learners work with matrices with a determinant...
American Institutes for Research
Digital Smiles
Explore metric measurement, recording data, and creating an electronic spreadsheet displaying results with your math class. Scholars will measure the length of their smiles, record the measurements, and represent the results on an...