EngageNY
Examples of Dilations
Does it matter how many points to dilate? The resource presents problems of dilating curved figures. Class members find out that not only do they need to dilate several points but the points need to be distributed about the entire curve...
EngageNY
Informal Proof of AA Criterion for Similarity
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
Concord Consortium
Shooting Arrows through a Hoop
The slope makes a difference. Given an equation of a circle and point, scholars determine the relationship of the slope of a line through the point and the number of intersections with the circle. After graphing the relationship, pupils...
Mr. Williams Maths
Eight Circle Theorems Page
Your learners will find these circle theorems nicely organized with diagrams included that present the geometric relationships between the circle circumference, chords, central and circumference angles and tangents.
Radford University
Triangles in Parallelograms
What's the point of looking at triangles when trying to draw parallelograms? Given three non-collinear points, pupils determine and justify all possible points that would create a parallelogram. They then analyze the four triangles that...
Curated OER
Triangle Exploration
Students are introduced to The Geometer's Sketchpad software while in the computer lab. They focus on triangles, horizontal lines, vertex and top parallel lines. Each student utilizes geometry to complete basic geometric constructions.
Curated OER
Kuta Software - Infinite Geometry: Similar Triangles
In this similar triangles worksheet, learners solve 20 short answer problems. Students determine if two given triangles are similar. Learners determine the type of similarity given two triangles. Students are given a sketch of the...
Curated OER
Kuta Software: Infinite Geometry - Classifying Quadrilaterals
In this classifying quadrilaterals worksheet, students classify 18 quadrilaterals in short answer format. Students use quadrilateral properties of classify quadrilaterals given a sketch.
Curated OER
Kuta Software - Angles in Quadrilaterals
In this angles in quadrilaterals worksheet, students solve 18 short answer problems. Students find unknown angles in a quadrilateral given a sketch of various quadrilaterals with unknown angle measurements.
Curated OER
The Trapping of Trapezoids
This is a nice hands-on activity where young geometers create trapezoids and calculate their area by looking at areas of quadrilaterals and triangles.
Curated OER
Tessel Your Way to Nagano!: Olympics, Winter Sports, Snowboarding, Graphic Design, Geometry, Math, M.C. Escher, Tessellations
Students create Post-It note fundamental regions to tesselate. They make tesselations using computer software or websites. They create a jacket design with tesselation and determine the cost of production.
Curated OER
Moving Day!
Eighth graders continue their geometry unit by focusing on volume. Using data, they create a spreadsheet, estimate and calculate volume. They solve real-life problems and round their answers to the hundredths place. They also practice...
Improving Measurement and Geometry in Elementary Schools
The Sum of the Interior Angles of a Polygon
Junior geometers discover that polygons can be decomposed into triangles and that the number of triangles can be determined by a rule. Note that the Geometer’s Sketchpad® software is required to carry out all components of this...
Curated OER
Exploring Perimeter
Students explore perimeter. For this geometry and measurement lesson, students create squares and rectangles using given perimeters. Students construct four sided shapes with given perimeters using the computer program "Math Keys:...
Texas Instruments
REAL LIFE REAL WORLD Activity - Surveyor
Learners investigate surveying in this secondary mathematics lesson. They will explore a real world application of geometry and trigonometry as they create a plot plan using a geometry utility and calculate the area of the land parcel.
Curated OER
Investigating a Point on an ANgles Bisector
Pupils investigate points and angle bisectors. In this geometry lesson plan, students define angles, bisectors and perpendicular bisectors. They analyze angles and bisectors using Cabri software.
Curated OER
Corresponding Sides and Angles of Similar Triangles
Young scholars differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
Curated OER
Orthocenter Of a Triangle
Students find the orthocenter of a triangle. In this geometry lesson, students identify where the altitudes meet in a triangle. They use Cabri software to explore acute, obtuse and right triangles.
Curated OER
SAS Similarity Theorem
Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
Curated OER
Similar Triangles on the Coordinate Plane
Students investigate triangles and their properties. In this geometry instructional activity, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or...
Curated OER
Properties of Special Parallelograms
Students identify properties of trapezoids. In this geometry lesson, students are put into groups and use computer programs to analyze polygons. They drag and move the shapes around as they make predictions.
Curated OER
Exploring Geometric Mean
Students solve problems using geometric means. In this geometry instructional activity, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.
Curated OER
Exploring Geometric Mean
Student identify the solution using geometric mean. In this geometry lesson, students create right triangles where the altitude of the triangle is the side containing the right angle. They modify shapes using Cabri software and observe...
Curated OER
Around the World With Geometry
Students identify shapes, create shapes, and make a pyramid, a drum, and a sail using their shapes. In this shapes lesson plan, students also identify plane and space shapes.