Curated OER
The Sum of All Angles
Pupils add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...
Curated OER
Nets, Surface Area and Volume
Learners calculate the surface area and volume of a sphere. In this geometry lesson, students define nets, surface areas and volume of prisms, pyramids, cylinders and cones. They use the computer to create nets and analyze shapes.
Mathster
Line and Rotational Symmetry
Challenge young mathematicians' understanding of symmetry. Provided with images of different shapes, letters, and national flags, students are tasked with identifying the lines of symmetry and order of rotational symmetry...
Concord Consortium
Short Pappus
It's all Greek to me. Scholars work a task that Greeks first formulated for an ancient math challenge. Provided with an angle and a point inside the angle, scholars develop conjectures about what is true about the shortest line segment...
Concord Consortium
Shooting Arrows through a Hoop
The slope makes a difference. Given an equation of a circle and point, scholars determine the relationship of the slope of a line through the point and the number of intersections with the circle. After graphing the relationship, pupils...
Curated OER
Geometric Figures and the Coordinate Plane
Sixth graders explore geometric figures. In this geometry lesson, 6th graders manipulate properties and relationships of geometric figures to identify objects on the coordinate planes and describe where figures sit on the planes.
Curated OER
Community Building
Students build different shapes using sketches. In this geometry lesson, students explore measurements and units as they build and create models of buildings. They use SketchUp to create and manipulate shapes.
Curated OER
Irregular Fractals
Students study and research irregular fractals and construct a few based on their research. Students practice pattern recognition skills and plane geometry skills calculating dimensions on the Fractured Pictures activity.
Curated OER
Unit Perimeters and Areas
Students use Geometers SketchPad to find the area and perimeter of several shapes. In this geometry lesson, students determine area of rectangles and progress through irregular polygons. None of the referenced worksheets are included...
Pennsylvania Department of Education
Tangram Challenges
Students explore geometric concepts by working with Tangram Puzzles. In this Tangram challenge instructional activity, students use problem-solving tasks that involve physical manipulatives. Students select a picture and use...
Curated OER
Symmetry: Theory, Reality and Art!
Learners explore the concept of geometric symmetry. In this geometric symmetry lesson, students walk around their school and take pictures of objects that demonstrate symmetry. Learners use Microsoft Paint to draw the lines of symmetry...
Curated OER
Placing Plates
Second graders investigate the task of making a large hexagonal plate by putting together smaller ones. The lesson has detailed example problems for the teacher to use during direct instruction. The manipulative activities strengthen the...
EngageNY
Construct an Equilateral Triangle (part 1)
Drawing circles isn't the only thing compasses are good for. In this first installment of a 36-part series, high schoolers learn how to draw equilateral triangles by investigating real-world situations, such as finding the location of a...
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence...
National Security Agency
What’s Your Coordinate?
Your middle schoolers will show what they know with their bodies when they become the coordinate plane in this conceptual development unit. Starting with the characteristics of the coordinate plane, learners develop their skills by...
National Security Agency
Backyard Building - Area and Perimeter
Turn young mathematicians into landscape architects with this four-lesson series on area and perimeter. Beginning with a basic introduction to calculating perimeter and area using non-standard units of measurement, this...
Curated OER
Exploring Harmonic Conjugates
High schoolers investigate harmonic conjugates using Cabri Software or the Ti Calculator to analyze harmonics. They explore different angles measurements as they move their circles around and solve problems.
Curated OER
Exploring Trigonometric Ratios
Students identify the ratios of trig functions. In this trigonometry lesson, students construct triangles and use it to derive the values of sine, cosine and tangent. They use Cabri software to create the visual of the identities.
Curated OER
What's My Ratio?
Students investigate ratios of various objects. In this ratios of various objects lesson, students draw pictures on graph paper and then dilate or shrink the image. Students determine the ratio of their pictures. ...
Curated OER
Gotcha Covered, Pardner!
Young geometers use the interactive website Cyberchase to practice calculating both area and perimeter. Real world problems encourage learners to discover that we use math each and every day.
Curated OER
Coordinate Plane Transformations
Geometric transformations are explored by high schoolers. They will create a set of instructions for plotting coordinates representing an original transformation of a real-world figure. These instructions are shared with middle...
Curated OER
Angles
Fourth and fifth graders investigate angles and name them according to the criteria for obtuse, acute, and right angles. They examine a human-made yarn pattern on the floor of their classroom and identify angles, vertices, and types of...
Curated OER
Visualizing Multiplication
Upper graders represent multiplication of a two-digit number by a two-digit number as the area of a rectangle with dimensions of the two factors. They find patterns for the number of different base ten blocks in a rectangle representing...