Worksheet
Curated OER

Basic Theorems and Proofs

For Students 11th
In this pre-calculus activity, 11th graders recall the three forms of the law of cosines and used it to solve problems involving triangles. They also write out the laws of sines and use those to solve problems with angles. There are 15...
Lesson Plan
Curated OER

Investigating Area Relationships

For Teachers 9th - 12th Standards
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.
Lesson Plan
Curated OER

Introducing Powers and Models

For Teachers 4th - 6th
Learners construct two dimensional models to illustrate squared numbers. In this geometry lesson, students use graph paper and an x/y axis to build squares exponentially. Learners identify powers and relationships between various figures...
Lesson Plan
Curated OER

Scalene Triangles

For Teachers 5th
Fifth graders identify and classify scalene, equilateral, and isosceles triangles. In this triangle lesson, 5th graders define the different attributes of 3 types of triangles and sort them by descriptions and...
Worksheet
Curated OER

Scalene Triangles

For Students 3rd - 4th
In this scalene triangles worksheet, students look over and analyze 11 triangles and determine which ones are scalene triangles.
Lesson Plan
Curated OER

Similar Triangles on the Coordinate Plane

For Teachers 9th - 10th
Students investigate triangles and their properties. In this geometry lesson, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or congruent.
Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
Students solve problems using geometric means. In this geometry lesson plan, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.
Lesson Plan
Curated OER

Why can't We Use SSA to Prove Triangles Congruent?

For Teachers 9th - 10th
Students investigate triangles and congruences. In this geometry instructional activity, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
Lesson Plan
Curated OER

Trig functions and Triangles

For Teachers 7th - 9th
Here is a basic plan for the beginning teacher to use for introducing the class to the right triangle trigonometric functions. It outlines the lesson objectives, class procedures, and basic instructional techniques that could be...
Lesson Plan
Curated OER

Origami Frogs

For Teachers 9th
Ninth graders explore a variety of geometry and science concept while making an origami frog. The fold paper into the shape of a frog and conduct measurement activities including frog leaps.
Lesson Plan
Virginia Department of Education

The Pythagorean Relationship

For Teachers 9th - 11th Standards
Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...
Worksheet
Curated OER

Crossword: Geometric Shapes

For Students 6th - 8th
Using a word bank, mathematicians fill out a crossword puzzle using 9 clues. Each clue describes a shape, using details such as the number of sides, angle degrees, and the shape category. For example: "A quadrilateral with four equal...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 10th
Students solve problems using the Pythagorean Theorem. For this geometry lesson,students identify the right angle, hypotenuse and legs of a right triangle. They find the missing sides using the ratios of the Pythagorean theorem.
Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
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...
Lesson Plan
Curated OER

Heron's Formula

For Teachers 9th - 10th
Learners use Heron's formula to calculate the area of a triangle. In this geometry lesson, students use three different methods to solve the area of a triangle. They find and construct the incentor and angle bisector of a triangle.
Lesson Plan
Curated OER

Circles, Rectangles, Squares, Triangles

For Teachers K
Students identify, compare and classify the various shapes. In this shapes lesson, students listen to descriptions of shapes with words such as sides, angles, congruent, and parallel. Students then give the teacher examples of shapes...
Lesson Plan
Curated OER

The Pythagorean Theorem

For Teachers 7th - 10th
Students research Pythagoras and learn how to apply his theorem. They solve real life problems using the theorem and demonstrate knowledge of exponents, equations, and radicals. Students include diagrams in their research papers.
Interactive
Curated OER

Arcs and Chords Multiple Choice

For Students 9th - 10th
In this geometry worksheet, students answer questions about triangles using the correct properties. They find missing angles and sides of triangles. There are 15 questions with an answer key.
Lesson Plan
Curated OER

Tri this Angle!

For Teachers 1st
First graders draw and describe various types of polygons. they investigate their own environments for examples of polygons. After reading the book, The Greedy Triangle, they discuss everyday objects that are polygons. They create shape...
Worksheet
Curated OER

Triangle Review

For Students 4th - 6th
In this triangle worksheet, students draw the type of triangles described, 4 total. Space is provided for student's drawings. A reference web site is given for additional activities.
Lesson Plan
Curated OER

The Distance to an Unapproachable Point

For Teachers 8th - 11th
Students use geometry or trigonometry to measure the distance of a far off point. They verify their measurements using a tape measure to check their work.
Lesson Plan
Curated OER

Math: Investigating Triangles

For Teachers 10th
Tenth graders identify the trigonometric ratios for right angled triangles. Through independent investigation, they discover the constancy between the ratios of any two sides of similar triangles. In an alternative method, 10th graders...
Worksheet
Curated OER

Constructions and Loci

For Students 9th - 10th
In this geometry worksheet, students construct polygons and calculate the different angles formed by each shape. They construct circles, trapezoids, and rectangles and answer 20 questions.
Worksheet
Curated OER

1st Geometry

For Teachers 3rd - 6th
In this geometry worksheet, students choose the multiple choice answer to 15 questions involving several different elements of geometry.