GeoGebra
Conjectures and Proof
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
101 Questions
Best Reflection
Which is the best reflection of them all? Given four diagrams, pupils determine which one shows the most accurate reflection of a quadrilateral. Two images provide the distances of each vertex from the line of reflection, as well as the...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
Curated OER
Regents Exam Questions GG 10: Solids
In this solids worksheet, students identify true statements that match a given solid. They identify parallel lines. This two-page worksheet contains four problems. Answers are listed on the last page.
EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? In this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
Curated OER
Math: Symmetry and Similarity
Learners describe the differences between congruence and similarity. After explaining the motions that indicate congruency of two shapes, they complete worksheets to draw lines of symmetry and similar shapes. With straws and twist...
Curated OER
Reflections
Fifth graders create a reflection of a poygon using a Mira. They discover that a line connecting a vertiex of a polygon and the corresponding vertex of its reflection is perpendicular to the line of reflection. Students create a glide...
Curated OER
Quilt Geometry
Seventh graders explore lines of symmetry, congruent polygons and patterns. They listen to "The Seasons Sewn," observe a PowerPoint presentation, and identify congruent polygons and visual patterns. Through an internet activity, 7th...
Curated OER
Drawing Figures
Third graders draw shapes that are congruent. In this congruency lesson, 3rd graders use grid paper to draw letters and figures and their congruent partners. They complete a worksheet while working in a whole class setting with the...
Curated OER
Properties of Geometry
In this properties of geometry worksheet, 10th graders solve and complete 12 different problems that include various theorems. First, they draw a figure that illustrates the SAS inequality property. Then, students prove that two line...
Curated OER
Friendship Quilt
Third graders name different kinds of shapes and then discuss what they know about them an what they would like to learn using a K-W-L chart whole group. They listen to the book, THE GREEDY TRIANGLE and then retell it to the class. They...
Curated OER
Measuring Length: Practice A
Ninth graders investigate the segment addition postulate. In this geometry instructional activity, 9th graders explore the difference between equal and congruent in relation to segment length. The instructional activity includes an...
Curated OER
Verifying Segment Relationships
In this verifying segment relationships learning exercise, 10th graders solve two proofs by following the same format used in algebra. They complete each of two proofs by naming the property that justifies each statement given. Students...
Curated OER
NON-EUCLIDEAN GEOMETRY.
Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...
Curated OER
Fun With Symmetry
Students manipulate shapes to find multiple lines of symmetry. They use color to visualize the lines of symmetry.
Curated OER
Measurement of Angles
Young scholars measure angles that are formed by parallel lines and a transversal lines. In this angles lesson plan, students measure and define angles that are made by parallel and transversal lines. They will color code the angles...
Curated OER
Tangent Properties
Students explore properties of tangent lines. In this properties of tangent lines lesson plan, students discuss the perpendicular relationship between a tangent line on a circle and the circle's radius. Students use that relationship...
Curated OER
Challenge: Skills and Applications Lesson 1.3
In this skills worksheet, students explain the Segment Addition Postulate, provide examples and counter examples and determine congruent line segments. This one-page worksheet contains 11 multi-step problems.
Curated OER
Symmetry of Road Signs
Students identify symmetry in road signs. In this geometry lesson, students explore objects in the real world for symmetry. They perform translation, rotation and reflection.
Curated OER
Proofs
For this proofs worksheet, 10th graders solve and graph 8 different equations. First, they prove that each triangle is either congruent or similar. Then, students use the concept of corresponding parts of congruent triangles to solve...
Curated OER
Classifying Triangles
In this classifying triangles worksheet, 10th graders solve 9 various problems that classify triangles into categories. First, they refer to the figure shown of an isosceles triangle with two line parallel. Then, students name the sides,...
Curated OER
Quadrilaterals and their Diagonals
In this quadrilaterals and their diagonals instructional activity, 10th graders solve 3 problems related to determining various types of quadrilaterals. First, they draw the diagonals for each of the quadrilaterals and determine for...
Curated OER
Reflections over Two Lines & Dilations
Young scholars create reflections over two lines. In this reflections worksheet, students compare and contrast reflections over parallel and intersecting lines. They dilate figures and investigate the effect of the dilation using...
Curated OER
Right Triangles
In this right triangles activity, 10th graders solve 10 different problems that include determining the means proportionally in each right triangle. First, they use the given information to determine the measure of each line segment....