EngageNY
Analytic Proofs of Theorems Previously Proved by Synthetic Means
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
EngageNY
Special Lines in Triangles (part 2)
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
Curated OER
Connect the Mathematical Dots
Teachers can choose visual activities that demonstrate the elegance associated with the coordinate plane.
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
Mathematics Vision Project
Geometric Figures
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Curated OER
Amazing Triangles
Student scientists investigate triangle structures. In this building lesson plan, students explore how to design triangle braces in the construction of structures in order to build a stronger base.
Mathematics Vision Project
Module 5: Modeling with Geometry
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts to finding...
Curated OER
Pop-it...Stop-it
Learners observe how certain geometric shapes can be used to make some structures rigid and others flexible. The activity involves construction of a 30-60 right triangle, folding while following directions, and identifying polygons.
Curated OER
Area of Polygons
Learners engage in a lesson that is about the concept of polygons and focuses upon finding the area. They use formulas provided in the lesson in order to solve problems given by the teacher for independent practice. Geometric figures are...
Curated OER
Investigating Area Relationships
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.
Curated OER
Quadrilateral Attributes
Students classify quadrilaterals. In this quadrilateral lesson, students identify the characteristics of quadrilaterals. They write their findings in a journal. Students use geoboards to create quadrilaterals from given descriptions.
Curated OER
Wrecked Angle
In this geometry worksheet, students answer questions about triangles and trapezoids as it related to the area of a shape. They make their own polygons and calculate the area.
Curated OER
"Sir Cumference and the First Round Table" by Cindy Neuschwander
Students analyze characteristics of various 2 dimensional shapes and explore their properties and use various vocabulary terms to discuss geometric relationships.
Curated OER
Geometry
In this geometry review game worksheet, students use the provided game cards and calling cards to play a Bingo-like game. Students learn geometric terms while playing a group game.
Math Mammoth
Triangles 1
In this triangles learning exercise, students measure and calculate the measurements of eight triangles, their sums and classify the triangles as acute, obtuse or right.
Raytheon
Understanding Triangles
In this understanding triangles worksheet, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Curated OER
Origami Frogs
Ninth graders explore a variety of geometry and science concept while making an origami frog. The fold paper into the shape of a frog and conduct measurement activities including frog leaps.
Curated OER
Creating Shapes
In this geometry skills lesson, students respond to 4 questions that require them to examine the pictured shapes and follow the instructions to create new shapes out of them.
Curated OER
Polygons and Sketching
For this geometry worksheet, students define and draw quadrilaterals. They differentiate between the different shapes. There are 3 questions with an answer key.
Curated OER
Drawing Quadrilaterals
In this math instructional activity, learners draw quadrilaterals and also find the sums of the inner angles for each. They practice drawing rhombuses as unique quadrilaterals.
Curated OER
Exploring Lines of Symmetry
Students investigate the concept of symmetry. They use cut out shapes that are folded in order to practice identifying the lines of symmetry. The lesson is observed by the teacher working with students for the purpose of scaffolding and...
Curated OER
Math Review for Grade 3 (3.2)
In this math review for grade 3 (3.2) worksheet, 3rd graders answer 25 multiple choice questions in standardized test format.
Curated OER
Making Tangram Pieces by Folding Paper
Third graders follow directions to make a set of tangram pieces. After reading a story, they compare and contrast the differences between two-dimensional shapes. To end the lesson plan, they use the tangram pieces to create their own...