Worksheet
Curated OER

Construct, Bisect, Duplicate: Geometry Practice with Compass and Straight Edge

For Students 9th - 12th
Geometers employ a straight edge and compass to duplicate and bisect segments and angles, construct perpendiculars, parallel lines, figures, and circles with points of concurrency. Ample practice with 65 questions across 8 worksheets. No...
Instructional Video10:36
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Flipped Math

Inverse Trig Ratios

For Students 9th - 12th Standards
Put trigonometric ratios into inverse. Scholars learn how to find an unknown angle in a right triangle by using inverse trigonometric ratios. The pupils understand how the inverses undo a trigonometric ratio to provide the angle measure....
Lesson Plan
EngageNY

Prove the Pythagorean Theorem Using Similarity

For Students 9th - 10th Standards
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
Assessment
Concord Consortium

Short Pappus

For Students 9th - 12th Standards
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...
Unit Plan
Mathematics Vision Project

Module 7: Modeling with Geometry

For Teachers 9th - 12th Standards
Model good modeling practices. Young mathematicians first learn about cross sections and solids of revolution. They then turn their attention to special right triangles and to the Laws of Sine and Cosine.
Lesson Plan
Curated OER

The Ambiguous Case

For Teachers 9th - 10th
Students investigate the relationship of triangles with its sides and angles. For this geometry lesson, students create visual on the graphing navigator as they study triangles. They move the sides around to create different angle-side...
Worksheet
Curated OER

Law of Sines

For Students 10th
In this Law of sines worksheet, 10th graders solve 10 different sets of problems related to the Law of Sine and Ambiguous case. First, they determine the ratio of the sides of the triangle with the given measurements. Then, students...
Lesson Plan
Curated OER

Cabri Jr. Perpendicular Bisector of a Chord

For Teachers 9th - 12th Standards
Your learners will construct the perpendicular bisector of a chord. They use Cabri Jr. to construct a circle and a perpendicular bisector of a chord. They then measure lengths of the chords and perpendicular bisectors. Learners use...
Lesson Plan
Curated OER

Triangle Puzzler

For Teachers 5th - 8th
Students are introduced to some basic concepts of geometry. They explain that the definition of a triangle is a figure with three sides, three angles, and three points. Triangles can be named by using three points in their correct sequence.
Lesson Plan
Curated OER

Geometry of Triangles - Week 6

For Teachers 12th - Higher Ed
In this geometry of triangles worksheet, students find the length of sides, are, and angle measurement of inscribed triangles, pentagons, and midpoint of a line. This two-page worksheet contains seven problems.
Lesson Plan
Curated OER

Properties of Triangles

For Teachers 4th - 8th
Learners explore the relationship between how big a side of a triangle is and how big its opposite angle is by creating triangles using an interactive website.
Lesson Plan
Curated OER

Types of Triangles

For Teachers 1st - 2nd
Students classify triangles by the length of their sides. In this geometry lesson plan, students use a white board to demonstrate the angles of various triangles. Students construct an equilateral, isosceles, and a scalene triangle.
Lesson Plan
Curated OER

Geometry and Measurement

For Teachers 6th - 8th
Young scholars view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Young scholars use pegboards and string to...
Worksheet
Curated OER

Triangles and Congruence

For Students 8th - 10th
Can your class construct triangles and determine congruence? Find out with this well put together worksheet. THey construct triangles to given specifications and identify if they are congruent. There are 3 muti-step problems to solve.
Worksheet
Curated OER

Classify Triangles

For Students 4th - 7th
Here is a classifying triangles practice worksheet in which learners sharpen their problem solving skills as they solve six story problems.
Worksheet
Curated OER

Attributes of Shapes Guided Lesson Explanation

For Students 1st
Triangles, circles, and rectangles are featured in a colorful, one-page worksheet that defines and illustrates these shapes. Read the explanations with your first graders and have them count the number of shapes in a given box. Since the...
Worksheet
Curated OER

Special Segments is a Triangle

For Students 10th
In this geometry worksheet, 10th graders examine the special segments that occur in a triangle.  The three page worksheet contains twenty-five problems.  Answers are not included. 
Handout
Lockport City School District

Reasons for Geometric Statement/Reason Proofs

For Students 8th - 11th Standards
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 
Lesson Plan
Curated OER

Analyzing Congruence Proofs

For Teachers 9th - 12th Standards
Looking at numerous examples of triangles, each with different properties, geometers develop their understanding of congruency. They use the notation of a counter-example to disprove certain conjectures and prove geometric theorems and...
Worksheet
Curated OER

Sort Triangles and Quadrilaterals

For Students 4th - 5th
In this triangle/quadrilateral worksheet, learners solve 6 problems that ask questions about lengths, parallel line and angles of quadrilaterals and triangles.
Lesson Plan
Curated OER

Review Geometry - Week 8 (Triangles)

For Teachers 11th - 12th
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
Lesson Plan
Curated OER

Angles and Similarity

For Teachers 9th - 12th Standards
High schoolers identify triangles as similar or congruent. In this geometry lesson, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 8th - 10th
Learners use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
Interactive
Curated OER

All About Quadrilaterals

For Students 7th
In this quadrilateral post test worksheet, 7th graders answer ten multiple choice questions by solving questions based on quadrilaterals and angles of quadrilaterals. This is an interactive worksheet.