Alabama Learning Exchange
What You Know About the Bermuda Triangle?
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
McGraw Hill
Triangles
After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of similar...
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...
K-5 Math Teaching Resources
Triangle Pack
With so many different types of triangles, it can be a challenge for young mathematicians to keep them all straight. Luckily this set of printable triangles is here to engage children in comparing and sorting triangles by their...
Scholastic
Study Jams! Classify Triangles
Jam on with this multi-faceted activity teaching triangle classification. Start with a learner-paced lesson describing the different qualities of triangles and follow with a fun karaoke session. Also provided are two types of...
Curated OER
Acute Triangles
Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.
Curated OER
Right Triangles
Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...
Curated OER
Classifying Triangles
If you're looking for a presentation to assist you in your teaching of triangles, this one could be for you. In it, learners are shown how triangles are classified by the size of their angles and by their sides. These are tricky concepts...
Curated OER
Obtuse Triangles
Fourth graders explore obtuse triangles. In this geometry lesson, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.
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
Toothpick Triangles
Students draw a chart (included in the instructional activity) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the instructional activity. Beginning with three toothpicks, students...
Texas Instruments
Identifying a Triangle by its Sides and Angles
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
Curated OER
Easy Worksheet: Classify the Triangle
In this classify the triangle worksheet, students solve 6 short answer problems. Students identify the type of triangle being described according to its angle measures and side lengths.
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...
Bowland
Rods and Triangles
Scholars explore triangles with rods of different lengths. Using rods of 2, 4, 6, 8, and 10 cm class members build as many different types of triangles as they can. They also describe properties of these triangles and determine...
National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy Triangle,...
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...
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.
Curated OER
Study Buddies: Classifying Triangles
In this math worksheet, pupils analyze an informative chart about the measurement and angles of equilateral, isosceles and scalene triangles. Students then answer 5 questions about classifying triangles.
Curated OER
Geometry of Triangles - Week 6
In this triangle worksheet, students explore the characteristics of triangles. They find the area of a pentagon, lengths of the sides of a triangle and the area of a quadrilateral. This two-page worksheet contains seven problems.
Curated OER
Triangle Designs
In this triangles worksheet, students draw different triangles and write how many sides and angles each one has. Students draw 4 kinds of triangles and have 2 that are impossible to draw.
Curated OER
Triangles
In this triangles worksheet, 4th graders study the lengths that are stated for 3 triangles and describe each triangle by its sides. Students describe 3 additional triangles by their angles.
Curated OER
Classify Triangles
Here is a classifying triangles practice instructional activity in which learners sharpen their problem solving skills as they solve six story problems.
Curated OER
Identifying Triangles
In this triangles practice worksheet, students respond to 4 questions that require them to identify the pictured triangles as acute, right, obtuse, scalene, isosceles, or equilateral triangles.