Math Solutions
Shape Sorting: Looking for Green!
Young mathematicians rotate, flip, and sort their way to an understanding of the different attributes of geometric figures. Using transparent yellow and blue shapes, children try to match congruent figures together...
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Bowels Physics
Refraction and Lenses
Every object we see must pass through a lens, but how does each individual's lens differ? Learners explore the science behind refraction and lenses, uncovering the details that allow them to perform daily activities.
Illustrative Mathematics
Are These Right?
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
Curated OER
Angle-Side Relationships
Students calculate the different sides and angles of a triangle. In this geometry lesson, students use triangular properties to define the relationship between two triangle. They identify missing angles using the interior angle theorem.
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
Curated OER
CSI Investigation of Congruence and Similarity
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
101 Questions
Best Triangle
What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...
Curated OER
New Angle on Forest Ecology
Young scholars measure and calculate the angle of the sun. They compare the leaf types on the north and south to compare the effects of the sun on the type of vegetation. They complete the activities inside the classroom or on a trip to...
Curated OER
Investigating AAS
Students investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, students discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by two rays...
Everyday Mathematics
Mathematics Within: Slope and Triangles
Learners discover a method for determining the slope of a line by creating and comparing similar triangles. They fold coordinate grids to make three similar triangles then measure the sides to compare the relationships between the...
EngageNY
Applying Tangents
What does geometry have to do with depression? It's an angle of course! Learners apply the tangent ratio to problem solving questions by finding missing lengths. Problems include angles of elevation and angles of depression. Pupils make...
Curated OER
Sin, Cos and Tangent
Students find the identity o sine, cosine and tangent. In this precalculus instructional activity, students solve and identify the different parts of a right triangle. They use the ratios of the Pythagorean Theorem to find the missing...
Curated OER
Investigating Area and Perimeter of Polygons.
Student sinvestigate the area and perimeter of polygons. They differentiate between similar and congruent polygons.. They identify the ratio and proportions of the sides and angles of polygons.
Curated OER
Atomic Absorption Determination of Zinc and Copper in a Multivitamin
Advanced lab apprentices prepare zinc and copper solutions to which they will compare the same minerals from a multivitamin. Using absorption spectroscopy, they analyze the contents of the multivitamin for concentration. This lab can be...
EngageNY
Special Lines in Triangles (part 1)
Allow your pupils to become the mathematicians! Individuals explore the properties of a midsegment of a triangle through construction and measurement. Once they figure out the properties, learners use them to draw conclusions.
EngageNY
Scale Drawings
Are you searching for a purpose for geometric constructions? Use an engaging approach to explore dilations. Scholars create dilations using a construction method of their choice. As they build their constructed dilation, they...
Curated OER
Comparing Roots After Rotation of Ninety Degrees
Students conduct an experiment and use different measurements of a single root to illustrate the mechanism of plant movement.
Illustrative Mathematics
What is a Trapezoid? (Part 2)
This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...
Curated OER
Corresponding Parts of Similar Triangles
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...
Virginia Department of Education
Similar Figures
How similar do figures have to be to be similar figures? Individuals learn to identify similar figures by verifying that angles are congruent and sides are proportional. Additionally, they match the corresponding parts of similar figures.
Curated OER
Triangle Inequality Theorems Investigation
Students estimate and measure triangles. In this geometry instructional activity, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.
Curated OER
Reflections Of
Students create angles using mirrors. In this angle reflection lesson, students draw angles, then use mirrors to create angles using reflections and measure the new angles.