Curated OER
Exploring Secants: Products of Segments
Students explore secants and circles. In this geometry instructional activity, students identify the properties of two and three dimensional shapes. They create arguments to prove the theorems are true.
Curated OER
Exploring Properties of Rectangular Prisms
Young scholars explore the properties of rectangular prisms. In this geometry instructional activity, students identify properties of two and three dimensional shapes. They use Cabri technology to create polygons and solve problems.
Curated OER
Conjectures of Intersecting Circles
Students make conjectures of intersecting circles. In this geometry lesson, students observe circles and their position in space. They investigate and observe two and three dimensional objects.
Curated OER
Conjectures For Intersecting Circles
Students identify properties of circles. In this geometry lesson, students identify the center of two intersecting circles.They use Cabri software to create circles and move it around to make observation.
Curated OER
The Trappings of Trapezoids
Students define trapezoids and their shapes. In this geometry lesson, students calculate the area of a trapezoid and a parallelogram. They use Cabri software to make investigations.
Curated OER
Measurement of a Central Angle
Learners calculate the measurement of a central angle. In this geometry lesson, students identify properties of circles. They use Cabri software to create and analyze graphs.
Curated OER
Arc Measurement Based on The Measurement of a Central Angle
Students define keywords that are important to solve problems. In this geometry instructional activity, students find the arc length and angle of a circle. They convert between radians and degrees.
Curated OER
Exploring Chords: Products of Chord Segments
Students identify the properties of chords. In this geometry lesson plan, students multiply chord segments to find the solution to their problem. They construct two chords that cross on a circles.
Curated OER
Drawing a Perspective Floor
Tenth graders investigate the three D world of building. In this geometry lesson, 10th graders investigate math as it relates to the real world, increasing their perspective on mathematical concepts. They realize there is more to math...
Curated OER
Who Let the Dogs Out?
Students calculate the perimeter and area of polygons. In this geometry instructional activity, students apply formulas of perimeter to solve geometric problems. They calculate the area of a dog fence and create ways to keep the dog in...
Curated OER
Measuring Heights With Triangles
Young scholars identify the different properties of triangles. In this geometry instructional activity, students differentiate between congruent and similar triangles. They use mathematical reasoning to solve word problems.
Curated OER
Discovering Math: Concepts in Geometry
Middle and high schoolers explore the concept of proving the Pythagorean Theorem. They research proofs of the Pythagorean Theorem. Pupils create posters of proofs, and research Greek mathematicians.
Curated OER
Mathematics Within: Algebraic Processes and Its Connections to Geometry
Learners analyze multiple strategies of multiplication: clustering, area model, breaking apart/decomposing, etc. They create their own strategies to approaching multiplication problems and share them with their classmates. Discussion...
Curated OER
Geometry
Fourth graders explore symmetry and congruent figures. They draw letters of the alphabet that have symmetry, draw congruent figures, draw figures on dot paper, and complete three worksheets.
Curated OER
Geometry Fun
Students learn the basic definitions of a quadrilateral, parallelogram, rectangle and square and explain the relationship/classification process between them.
Curated OER
Kindergarten: Geometry in Our World (Centers)
Students identify attributes in real-life objects and models of solids and connect these attributes to characteristics of shapes such as circles, triangles, squares, and other rectangles. They discuss the ability of the object to roll,...
Curated OER
SuperShapes, Part 1; "Tri"ing Triangles
An outstanding lesson on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...
Curated OER
Tangram Geometry
Students listen to a story involving Tangram pieces. Students use Tangram pieces to complete shapes using an outline of a design.
EngageNY
Properties of Tangents
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...
EngageNY
Unknown Length and Area Problems
What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.
EngageNY
Equations for Tangent Lines to Circles
Don't go off on a tangent while writing equations of tangent lines! Scholars determine the equations for tangent lines to circles. They attempt both concrete and abstract examples, such as a tangent line to the unit circle through...
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Illustrative Mathematics
Shortest Line Segment from a Point P to a Line L
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the...
EngageNY
The Inscribed Angle Alternate – A Tangent Angle
You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their...