CK-12 Foundation
Conjectures and Counterexamples: An Extra Slice!
Class members will eat up an enticing interactive that lets users change the location of cuts made into a pizza to adjust the number of created slices. They create a counterexample for a conjecture on the number of slices.
Bytes Arithmetic
Geometry Pad+
Graphing paper, pencil, ruler, protractor, and compass, all get replaced or supplemented with this dynamic geometry application. Here, you can create, move, and scale many different shapes, as well as, explore and change their properties...
Curated OER
Getting it Right! An Investigation of the Pythagorean Theorem
In order to learn about the Pythagorean Theorem, young mathematicians investigate relations and patterns between different sides of a right triangle to look for possible relations among the squared sides. Once they have established the...
Curated OER
Polygon Sum Conjecture
In this geometry instructional activity, 10th graders identify the missing angles using the polygons sum conjecture. They measure exterior and interior angles using their angle theorems. There are 63 problems.
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...
Curated OER
Circle Conjectures
Students are given diagrams and are asked to make a conjecture. In this geometry lesson, students make conjectures of circles. They complete a lab activity to reinforce making conjectures. The first activity addresses a common core...
Curated OER
Polygon Sum Conjecture
Students calculate the sum of the angles of a polygon. For this geometry lesson, students use the interior angle formula of polygon based on the number of sides of the polygon. They identify the missing angle using algebra.
Curated OER
Conjectures and Conclusions
Students draw conclusions and make conjectures given a specific scenario. In this geometry lesson plan, students model real life scenarios using properties of triangles. They model number facts and explain why the outcome is what it is.
Curated OER
Triangle Conjectures
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. For this geometry lesson, 10th graders 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...
Curated OER
Contructions and Conjectures
Students make constructions and conjectures. In this geometry lesson, students construct right, acute and obtuse angles using a straight edge and a protractor. They investigate parallel lines and the angles formed by the angles.
Curated OER
Probability and Geometry
Students explore the ways Geometry can help solve probability problems. Students describe platonic solids and practice calculating probability using an online resource. They construct dice with various numbers of sides to demonstrate...
Mathematics Vision Project
Module 3: Geometric Figures
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
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
Finite Geometry
Young scholars solve for the area and perimeter of polygons. In this geometry lesson, students identify repeated patterns and create formula to solve problems. They make conjectures and prove hypotheses.
Curated OER
Geometry, Measurement & Reasoning
Students complete worksheets involving rotational symmetry. In this geometry lesson, students complete worksheets to identify rotational symmetry and rotations. They compare and contrast rotated figures. Students examine the relationship...
Curated OER
Geometry, Measurement & Reasoning
Students construct two-column proofs. In this geometry activity, students use deductive reasoning and geometric properties to justify given geometric statements. Students compare and contrast proofs.
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...
Curated OER
Geometry Jeopardy
Students identify the pattern in a problem. In this geometry lesson, students make predictions, collect and analyze data. They apply the idea of scales and measurements to the real world.
Curated OER
Geometry: Classifying Quadrilaterals
Students use construction technology to identify and find relationships between the attributes of various quadrilaterals. They make and test conjectures about the distinguishing properties of parallelograms, rectangles, rhombuses,...
Curated OER
Indirect Proof and Inequalities in one Triangle
In this geometry worksheet, 10th graders complete an indirect proof and order the sides or angles of a triangle. Also, students determine if a triangle can have sides with the given lengths. The two page worksheet contains twelve...
EngageNY
Circles, Chords, Diameters, and Their Relationships
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
EngageNY
How Do Dilations Map Lines, Rays, and Circles?
Applying a learned technique to a new type of problem is an important skill in mathematics. The lesson asks scholars to apply their understanding to analyze dilations of different figures. They make conjectures and conclusions to...
Curated OER
You Must Still Think Yourself, CAS Can Only Help
Have the class learn about and make conjectures about a line intersecting a cubic. In this making conjectures about a line intersecting a cubic lesson, students draw lines that intersect a cubic at three different points. Students...