Curated OER
Solving Problems Using Triangle Inequality Theorem
Sixth graders investigate triangles and the inequality theorem. They will collaborate in groups to determine the length of a longest side of a triangle. Then relate the size of the triangle to its angles using protractors, yard sticks,...
Curated OER
Triangle Inequality Theorems Investigation
Students estimate and measure triangles. In this geometry instructional activity, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.
Curated OER
Triangle Inequality Theorem
High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...
Curated OER
Triangle Inequality
Students discover that the sum of the lengths of any two sides of a triangle must be greater than the third side. They are shown how a triangle is formed using three strips such as that the triangle is seen inside the strips.
Virginia Department of Education 
How Many Triangles?
Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...
Curated OER
Triangle Inequality Theorem
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...
Curated OER
Indirect Proof and Inequalities in one Triangle
In this geometry worksheet, 10th graders complete an indirect proof and order the sides or angles of a triangle. Also, students determine if a triangle can have sides with the given lengths. The two page worksheet contains twelve...
Curated OER
Triangle Inequality Theorem
Students identify properties of triangles. In this geometry lesson plan, students create triangles using three different segments. They make conjectures and predictions.
Curated OER
Toothpick Triangles
Learners draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...
Curated OER
Drawing Straws
Fourth graders examine the Triangle Inequality Theorem by investigating possible lengths of the sides of a triangle.
Curated OER
Inequalities and Triangles
Students prove and apply theorems of triangle inequality and hinge theorem. In this geometry lesson, students will discuss which triangle is bigger and why. They will use theorems, such as Exterior Angle Inequality or the Pythagorean...
Alabama Learning Exchange
Is It a Triangle?
Students explore the concept of triangle inequalities.  For this triangle inequality lesson, students cut spaghetti noodles into given lengths.  Students use the noodles to complete a worksheet about triangle...
Curated OER
Triangles Congruency Theorems
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
Curated OER
Triangle Sum Theorem
Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. For this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how...
Curated OER
Napolean Triangle
Young scholars investigate the Napoleon triangle theory. For this polygon lesson, students  differentiate between the boundary points, interior and lattice point of a polygon. They apply concepts of equilateral triangles to...
Curated OER
Worksheet 7: Slope and Tangents
Providing both review and practice problems, this worksheet prompts students to answer five questions having to do with slope, tangents lines, graphing, the Squeeze Theorem, differentiable functions and derivatives. This activity could...
Curated OER
Which Triangles are Right
Students apply properties of right triangles to solve problems. In this geometry lesson, students identify axioms and theorems using examples.
Curated OER
Indirect Proof and Inequalities in One Triangle
In this geometry worksheet, 10th graders order the sides and angles of a triangle and determine the range of the third side of a triangle given the lengths of two sides.  The one page worksheet contains sixteen questions. ...
Curated OER
Exploring the Hinge Theorem
Learners explore the application of Hinge Theorem. In this geometry lesson, students write inequalities, given two sides of a triangle. They solve problems with triangular inequalities using the proper theorem.
Curated OER
Triangle Conjectures
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. For this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
Curated OER
Angle-Side Relationships
Students calculate the different sides and angles of a triangle. In this geometry lesson, students use triangular properties to define the relationship between two triangle. They identify missing angles using the interior angle theorem.
Curated OER
Geometric Patterns
Students explore geometric patterns.  Given three straws of various sizes, students conduct tests, and search for patterns, to determine if the various sizes would form a triangle.  They use the Triangle Inequality Theorem to determine...
Curated OER
CSI Investigation of Congruence and Similarity
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
Curated OER
Geometry Jeopardy
Students identify the pattern in a problem. In this geometry lesson, students make predictions, collect and analyze data. They apply the idea of scales and measurements to the real world.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
