Curated OER
Getting It Right! An Investigation of the Pythagorean Theorem
Learners construct a variety of right triangles using a right-angled set square, cutting corners from pieces of paper or cardboard, and using dynamic geometry software. They measure the sides of these various right triangles and record...
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
Inscribing a Circle in a Triangle
Pupils investigate inscribing a circle in a triangle. They use Cabri Jr. to draw a triangle, locate the incenter, and use the distance from the incenter to a side of the triangle to inscribe a circle. The dynamic nature of the geometry...
Curated OER
Fractal and the Dragon Curve
Students explore Fractal designs. In this geometry lesson, students observe the different polygons created in nature and relate it to math. They define polygons on planes and rotate polygons about a point.
EngageNY
Parallel and Perpendicular Lines
Use what you know about parallel and perpendicular lines to write equations! Learners take an equation of a line and write an equation of a line that is parallel or perpendicular using slope criteria. They then solve problems to...
Curated OER
Area of Circles and Probability
Students investigate the area of squares and circles. In this geometry lesson, students calculate the area and probability of simple events. They work on a laptop using Safari.
Curated OER
Pythagorean Theorem: Triangles and Their Sides
Students investigate triangles and their relationship to each other. In this geometry lesson, students solve right triangles using the properties of the Pythagorean Theorem. They differentiate between right, acute, straight and oblique...
Curated OER
The Dragon Curve Fractal
Learners identify the properties of a dragon curve. In this geometry instructional activity, students identify sequences and patterns as they solve fractals. They investigate patterns found in nature.
Curated OER
Geogebra Basics
Students identify basic geometric shapes using Geogebra. In this geometry instructional activity, students work on a laptop as they explore different geometric shapes. They calculate the area and perimeter of triangles.
Curated OER
Exploring the Centroid of a Triangle
Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...
Curated OER
Investigating Lengths of Segments in a Triangle
Pupils explore the midsegment of a triangle in the geometry lesson. They draw and measure the segment joining the midpoints of the two sides of a triangle and compare its length to the length of the third side of the triangle. The...
Curated OER
Perpendicular Bisector of a Line Segment
High Schoolers investigate the perpendicular bisector of a line segment. They use Cabri Jr. to construct the perpendicular bisector of a segment. The dynamics capabilities of Cabri Jr. allow your learners to observe the lengths of the...
Curated OER
Segments Formed by Intersectiong Chords, Secants, and Tangents
Learners investigate the properties of segments formed which chords, secants, and tangents, intersect. The dynamic nature of Cabri Jr. allows high schoolers to form and verify conjectures regarding segment relationships.
Curated OER
Altitude, Median, and Angle Bisector of a Triangle
Learners investigate the special properties of an altitude, a median, and an angle bisector and explore how these special segments divide the area of a triangle. The dynamic nature of Cabri Jr. allows pupils to form and verify conjectures.
Curated OER
Circle, Secants
Young scholars identify the secant segment of a circle. In this geometry lesson, students investigate secant lines formed outside the circle. They use Cabri software to create drawings and explore circles and secants.
Curated OER
Exploring Secants: Products of Segments
Pupils explore secants and circles. In this geometry lesson, students identify the properties of two and three dimensional shapes. They create arguments to prove the theorems are true.
Curated OER
Incenter of a Triangle
Tenth graders explore the properties of the incenter of a triangle. In this geometry lesson, 10th graders construct a triangle and the angle bisectors of each angle. The dynamic properties of Cabri Jr. allow students to locate and...
Curated OER
Investigating Area and Perimeter of Polygons.
Student sinvestigate the area and perimeter of polygons. They differentiate between similar and congruent polygons.. They identify the ratio and proportions of the sides and angles of polygons.
Curated OER
Similarity and Dilations - Discover Properties of Similar Figures
Learners investigate properties of similar figures. For this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...
Curated OER
Hit and Run
Pupils explore data collection in this instructional activity. They investigate distance vs. time and velocity vs. time graphs using information collected with a CBR 2 to simulate the reconstruction of an accident.