Curated OER
Spiral Symmetry
Taking the notion of symmetry to the next level, this looks at combining rotation and translation symmetry to build spiral symmetry in three dimensions. Using the Zome modeling system and an instructor’s guidance, geometers try to build...
Futures Channel
Folding Circles
Students investigate properties of circles. In this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Curated OER
Length, Perimeter, and Area
Students explore the concepts of length, perimeter, and area. In this math lesson, students use Shape Explorer to practice finding length, perimeter, and area.
Curated OER
Transformations and Rotations
Students define and identify transformation and rotation. In this geometry activity, students define rotations as congruence or isometry. They find the coordinates of an image and pre-image.
Texas Instruments
REAL LIFE REAL WORLD Activity - Surveyor
Learners investigate surveying in this secondary mathematics lesson. They will explore a real world application of geometry and trigonometry as they create a plot plan using a geometry utility and calculate the area of the land parcel.
Curated OER
Rotations in the Plane
Pupils investigate the properties of a rotation as they use technology (Cabri, Jr.) to observe the relationship between the pre-image and the image formed by the rotation. The lesson provides ample opportunity for learners to conjecture...
Curated OER
Transformations: Translations
High schoolers perform transformations and translations using polygons. In this geometry lesson, students perform transformations on a coordinate plane. They identify the image and pre-image of each figure.
Curated OER
Geometric Shape Cakes
Students become problem solvers and communicate geometrical ideas. In this geometrical shapes activity, students make a cake template from geometrical shapes.
Curated OER
Length, Perimeter and Area
Learners analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationship
Curated OER
Rep Tiles
Third graders use pattern blocks of one shape at a time to try to create a similar shape. They compare the perimeter of the new figure with the perimeter of the original shape and look for a pattern. Students use the pattern to predict...
Curated OER
Sail Problem
High schoolers explore the proportional relationships involved in multiple parallel lines being cut by a transverse line. They complete a sail design problem, that involves finding the lengths of pieces of fabric along the edge of a sail...
Curated OER
Shapes with Sticks
Third graders investigate three dimensional shapes. They examine a variety of shapes and the relationship between the number of faces, edges, and vertices. Students determine Euler's formula and they create a variety of three dimensional...
Curated OER
Geometry and Quilting
Fourth graders combine geometry and language arts skills while examining quilt-making. After identifying the geometric shapes contained in quilts, they write stories to encompass the quilt border. Students conclude by creating and...
Curated OER
End of the Year Math Terms
In this end of the year math test instructional activity, 4th graders complete problems including addition, division, measurement, decimals, and more. Students complete 22 problems.
Curated OER
Translations, Reflections, and Rotations
High schoolers are introduced to the concepts of translation, reflection, and rotation. They practice translating, reflecting, and rotating two-dimensional objects on the coordinate plane. students use computers to learn about the three...
Curated OER
Solving Trigonometry Problems in Two and Three Dimensions
In this Pre-calculus/Trigonometry worksheet, students solve trigonometry problems in two and three dimensions. The eleven page worksheet contains explanation, examples, and twenty problems. Answers are not included.
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
Homeschool Math
Homeschool Math: Triangles
This lesson plan provides students with an opportunity to practice drawing and measuring triangles and angles. It also shows pictures and gives definitions of each type of angle and triangle.
Cuemath
Cuemath: Obtuse Triangle
In this mini-lesson, learn about obtuse triangles including the obtuse triangle definition, sides, properties, examples, and other fun facts related to it.
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
CK-12 Foundation
Ck 12: Elem Math: Classifying Right Obtuse or Acute by Angle Measure
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to classify triangles based on angle measures.
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
Math Open Reference
Math Open Reference: Acute Angle
Learn about acute angles with this helpful reference tool. Provides a detailed definition, images, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.