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
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
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
Triangles with Collinear Circumcenters
Students identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
Exploring Geometric Figures
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain...
Curated OER
Spherical Geometry: A Global Perspective
Students investigate spherical geometry using a globe and an apple. In this spherical geometry lesson plan, students translate Euclidean geometry terms to spherical geometry terms using a globe. They answer 3 questions about spherical...
EngageNY
Square Roots
Investigate the relationship between irrational roots and a number line with a resource that asks learners to put together a number line using radical intervals rather than integers. A great progression, they build on their understanding...
Curated OER
A Lesson on the Root Spiral
Students create lines and shapes with a compass and a straight edge. In this geometry lesson, students investigate square roots, irrational numbers and spirals. They explore nature to see the shapes representing mathematics and geometric...
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.
Curated OER
The Overlooked Regular Pentagon
Tenth graders discuss the history of geometry as it relates to pentagons. In this geometry lesson, 10th graders solve problems of a pentagon inscribed inside of a circle using ratio. They review other properties for shapes of polygons...
Curated OER
Duplicating Segments and Angles
Tenth graders investigate geometric construction. In this geometry lesson, 10th graders explore the procedure for copying an angle and a segment. The lesson emphasizes the difference between a sketch, a drawing, and a...
Curated OER
Hexagoning the Circle
Learners explore similarity to see that the area of a circle should be a constant times the square of its radius. Students create a hexagon. Learners share their designs with the class.
Curated OER
Navigation Across the Seas
Young scholars examine nautical navigation and discover the differences between nautical charts and other types of maps or charts. Students practice setting a course, taking a bearing, and dead reckoning. This gives young scholars an...