+
Worksheet
Curated OER

To Be a Triangle Or Not To Be a Triangle?

For Students 10th
In this triangles worksheet, 10th graders solve and complete 10 different problems that include applying the Triangle Inequality Theorem. First, they use the illustrated triangles and the data table to test the theorem. Then, students...
+
Worksheet
Curated OER

Countdown Challenge: Triangle Inequality Theorem

For Students 7th - 8th
In this triangle inequality activity, students test the Triangle Inequality Theorem. They measure the sides of given triangles, identify the type of triangle, and name angles in the triangle. The one-page activity contains 36 problems.
+
Lesson Plan
Curated OER

Triangle Inequality Theorems Investigation

For Teachers 9th - 10th
Learners estimate and measure triangles. For this geometry lesson, 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.
+
Lesson Plan
Curated OER

Indirect Proof and Inequalities in one Triangle

For Teachers 10th
For 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...
+
Lesson Plan
Virginia Department of Education

How Many Triangles?

For Teachers 9th - 11th Standards
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 same...
+
Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 9th - 12th Standards
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...
+
Interactive
CK-12 Foundation

Pythagorean Theorem to Classify Triangles: Missing Angles

For Students 8th - 12th Standards
Learn to use the Pythagorean Theorem with non-right triangles. Pupils use the interactive to discover the relationship between the lengths of sides for acute and obtuse triangles. They compare the squares of the sides of the triangles to...
+
Worksheet
Curated OER

Quiz: Triangle Inequality Theorem

For Students 7th - 8th
In this triangle inequality theorem worksheet, learners determine the lengths of the sides of triangles and identify the measure of angles. This one-page worksheet contains ten triangle theorem problems.
+
Worksheet
Curated OER

Triangle Inequalities Homework

For Students 10th - 11th
In this geometry instructional activity, students solve problems based on the triangle inequality theorem(s) in which determine if the given lengths can form a triangle, given two sides of a triangle determine the range of the third...
+
Lesson Plan
Curated OER

Triangle Inequality Theorem

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

Triangle Inequality Theorem

For Teachers 7th - 9th
Students identify properties of triangles. In this geometry lesson, students create triangles using three different segments. They make conjectures and predictions.
+
Lesson Plan
Curated OER

Inequalities and Triangles

For Teachers 9th - 10th
Students prove and apply theorems of triangle inequality and hinge theorem. In this geometry activity, students will discuss which triangle is bigger and why. They will use theorems, such as Exterior Angle Inequality or the Pythagorean...
+
Lesson Plan
Curated OER

THE TRIANGLE INEQUALITY IN ANIMATION

For Teachers 9th - 12th
Learners open up the script to generate the sketch. They examine the viewing of the animation of a triangle. Students incorporate writing skills across the curriculum within this instructional activity.
+
Lesson Plan
Curated OER

Napolean Triangle

For Teachers 9th - 11th
Students investigate the Napoleon triangle theory. In this polygon lesson, students  differentiate between the boundary points, interior and lattice point of a polygon. They apply concepts of equilateral triangles to solve problems.
+
Printables
Virginia Department of Education

High School Mathematics Geometry Vocabulary Word Wall Cards

For Teachers 9th - 10th
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
+
Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 22 different problems related to various types of triangles. First, they name the shortest and longest sides and the smallest and largest angles in each of triangles...
+
Lesson Plan
Curated OER

Indirect Proof and Inequalities in One Triangle

For Teachers 10th
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.  Answers are...
+
Lesson Plan
Alabama Learning Exchange

Is It a Triangle?

For Teachers 9th - 12th Standards
Learners explore the concept of triangle inequalities.  In this triangle inequality lesson, students cut spaghetti noodles into given lengths.  Learners use the noodles to complete a worksheet about triangle inequalities.  Students...
+
Lesson Plan
Curated OER

Which Triangles are Right

For Teachers 9th - 10th
Students apply properties of right triangles to solve problems. In this geometry lesson, students identify axioms and theorems using examples.
+
Lesson Plan
EngageNY

Finding Systems of Inequalities That Describe Triangular and Rectangular Regions

For Students 9th - 12th Standards
How do you build a polygon from an inequality? An engaging lesson challenges pupils to do just that. Building from the previous lesson in this series, learners write systems of inequalities to model rectangles, triangles, and even...
+
Worksheet
Curated OER

Properties of Geometry

For Students 10th
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...
+
Lesson Plan
Curated OER

Triangle Wars

For Teachers 5th - 8th
Students explore geometry by participating in a class card game. In this triangle lesson, students utilize playing cards with shapes on them which they group up and discard, similar to "Old Maid." Students complete a worksheet and answer...
+
Worksheet
Curated OER

Triangle Inequalities

For Students 9th - 10th
In this geometry learning exercise, students use the inequality theorem to figure out if three segments will make a triangle. They are given the measures of two segments and must figure out the third segment on their own. There are 20...
+
Lesson Plan
Curated OER

Triangle Conjectures

For Teachers 10th
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...