Mt. San Antonio Collage
Inequalities in a Triangle
Stuck with triangle proofs? Take a 180° and provide learners with a guided worksheet that tests their knowledge with triangle inequalities. The questions require different types of proofs that range in levels of difficulty.
Curated OER
Two Triangles' Area
Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation.
Curated OER
Triangle Inequalities Homework
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...
Curated OER
Triangles: Triangle Inequalities
Using SketchPad on their calculators to construct triangles, students measure exterior angles and remote interior angles of their constructed triangle. Students develop the triangle inequality from observation and exploration with their...
Curated OER
Art or Junk? Discovering the Triangle Inequality
Middle schoolers study the triangle inequality. They will identify, compare, and analyze attributes of two and three-dimensional shapes. Then they develop vocabulary to describe the attributes. They also use manipulatives to analyze the...
Curated OER
To Be a Triangle Or Not To Be a Triangle?
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...
Curated OER
SuperShapes, Part 1; "Tri"ing Triangles
An outstanding lesson on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...
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 Inequalities
In this triangle inequalities worksheet, 10th graders solve 10 different problems that include various types of triangles. First, they determine which side is the longest side of a triangle with given the exterior angle measurement....
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 same...
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
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
Learners 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.
Curated OER
Toothpick Triangles
Students 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
Classification of Triangle Measurement & Perimeter
In this classification of triangles worksheet, 10th graders identify and complete 8 different problems that include determining the measurement and perimeter of various types of triangles. First, they color all right, acute, and obtuse...
101 Questions
Best Triangle
What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...
Curated OER
Triangle worksheets
In this geometry worksheet, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
K12 Reader
Classifying Triangles
Bring math and reading informational text together with a reading comprehension lesson. After kids read about isosceles, scalene, and equilateral triangles, they answer five comprehension questions to demonstrate how they can use context...
EngageNY
Finding Systems of Inequalities That Describe Triangular and Rectangular Regions
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...
Charleston School District
The Sum of Angles in a Triangle
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the angles, the...
Utah Education Network (UEN)
Real World Equations and Inequalities
Use of the resource = Opportunities for increased learning. Learners must use equations and inequalities to solve real-world and geometric problems.
Curated OER
Geometry Journal: Isosceles Triangles
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
Radford University
Triangle Inequality Task
Not all triangles are created equal. A simple hands-on activity has learners investigate the side lengths of triangles. They use pipe cleaners to determine whether triangles of given side lengths can exist and then use the results to...
Flipped Math
Prove Triangles Similar
Show more than one way to prove similarity. Scholars learn three different methods to show two triangles are similar, Angle-Angle, Side-Side-Side, and Side-Angle-Side. Pupils practice applying these methods to determine whether two given...