Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. In this geometry instructional activity, students prove why SSA does not work as a true angle side relationship theorem.
Curated OER
Investigating AAS
Young scholars investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, students discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by two...
Curated OER
Deductive and Inductive Reasoning
Students differentiate between inductive and deductive reasoning. For this geometry lesson, students identify congruent figures and examine logos for congruency.
Curated OER
Properties of Parallelograms
Students identify different properties of parallelograms. In this geometry lesson, students complete problems that proves the theorems and properties of parallelograms. They graph the different shapes on paper.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Curated OER
Introduction to Fractals: Geometric Fractals
Students explore the concept of fractals. In this fractals lesson, students discuss Sierpinski's Triangle using an applet. Students discuss the patterns involved with fractals. Students discuss the area of Sierpinski's triangle as the...
Curated OER
Pythagorean Theorem
Students investigate the Pythagorean Theorem. In this seventh through twelfth grade geometery lesson, students explore the Pythagorean Theorem and its converse and use it to find the length of the missing side of a right...
Curated OER
The Sum of All Angles
Students 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
Pythagorean Theorem and Problem Solving
Students use the Pythagorean Theorem to solve problems. In this geometry lesson plan, students identify the properties of a right triangle. They find the missing side and angles of a right triangle.
Curated OER
Surface Area of Prisms
Students compute surface area and volume of prisms. In this surface area lesson plan, students find the surface area and volume of rectangular and triangular prisms. Independently, students use their computers to determine the volume,...
Curated OER
The Shortest Distance
Students, working on their GED, examine the steps used to resolve the unknown sides of a right triangle. They express the square root function as an exponential function and derive the distance formula using principles of geometry.
EngageNY
Tangent Segments
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
EngageNY
Unknown Angle Problems with Inscribed Angles in Circles
We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The lesson then...
Curated OER
Logical Relationship of Postulates & Theorems
In this postulates and theorems instructional activity, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram. They use the concept map to prove...
EngageNY
Applications of the Pythagorean Theorem
Examine the application of the Pythagorean Theorem in problem-solving questions. Pupils apply the theorem to find lengths when given different scenarios. They finish the 17th installment in an 18-part series by applying the theorem...
NASA
Pop! Rockets
Off they go — launching rockets is fun. The lesson plan contains templates to build paper rockets that can be launched from a PVC pipe launcher. Individuals or groups build the rockets and determine the shapes for their fins. Included...
Curated OER
Inductive and Deductive Reasoning
Students use logical arguments and inductive reasoning to make or disprove conjectures. After observing a teacher led demonstration, students discover that the deductive process narrows facts to a few possible conclusions. In groups,...
Curated OER
Rotation Symmetry
Students investigate the concept of symmetry by using various examples and performing independent practice with scaffolding provided by the teacher. They review reflection symmetry and cover the new rotation symmetry using manipuatives.
Curated OER
Line and Shape Game
Learners play the "space-breaker" game, in which they are required to create a picture using shapes or lines called out to them) to reinforce the concept of geometric shape and line.
Curated OER
DEAD MAN'S CURVE
Ninth graders, after being given a unique scenario and a task sheet on Dead Man's Curve, calculate and explain the force needed to keep a car on a curve using a set of formulas and a geometric property of circles. They utilize and create...
Curated OER
Polygons All Around Us!
Students explore the concept of polygon properties. In this polygon properties lesson plan, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Students identify different geometric shapes...
Curated OER
Line and Shape Game
Students create a picture of an actual scene or overlap the called out lines or shapes into a space-breaker. If someone calls out a line or shape a student had not planned to use in the art, they have to figure out some way to use it...
Maths Challenge
Maths challenge.net: Triangle Area
Find the area of this triangle in a coordinate plane.
Oswego City School District
Regents Exam Prep Center: Triangle Inequality Theorems
This tutorial discusses triangle inequality and provides practice problems for students to try out their skills. The teacher resource page contains a lesson plan for a yummy activity involving licorice.