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,...
CK-12 Foundation
Special Triangle Ratios: Special Right Triangle Ratios
Go from one side length to any other side length with special right triangles. Individuals use the interactive to investigate the ratio of sides in 45-45 and 30-60 right triangles. Scholars make generalizations about the types of special...
Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
Curated OER
Congruence of Triangles
In this congruence of triangles worksheet, 10th graders solve and complete 10 different problems that include measuring the congruence of various triangles. First, they determine the length of a third side of an isosceles triangle. Then,...
Curated OER
Lengths of Horizontal and Vertical Line Segments
Use this lengths of horizontal and vertical line segments practice worksheet to have learners sharpen their problem solving skills as they solve six story problems.
Curated OER
Triangles
In this triangle activity, students observe pictures of triangles. They name the triangles according to the length of their sides. Twelve right, equilateral and isosceles triangles are provided for identification on this one-page...
Curated OER
Classifying Triangles
In this classifying triangles learning exercise, learners explore given lengths or angle measurements and then classify each triangle as isosceles, scalene or equilateral. They also determine if the triangle may be right, acute or...
Curated OER
Classifying Triangles
This presentation shows how triangles are classified by angle measurement and length of sides. Â It reviews isosceles, scalene, obtuse, right, and acute classifications and includes questions for students to classify some of the triangles...
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
EngageNY
Triangle Congruency Proofs (part 2)
Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Mt. San Antonio Collage
Congruent Triangles Applications
Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the worksheet provides a brief introduction of the different properties and postulates. The remaining pages contain...
Curated OER
Isosceles Triangle Investigation
Students solve problems with isosceles triangles. For this geometry lesson, students identify and use the properties of triangles to solve their problems. They find the median, altitude, and angles to the triangles.
Curated OER
Triangles
For this triangles worksheet, students identify 3 triangles by the length of their sides and 3 triangles according to their internal angles.
Curated OER
Geometry of Triangles - Week 6
In this geometry of triangles worksheet, pupils find the length of sides, are, and angle measurement of inscribed triangles, pentagons, and midpoint of a line. This two-page worksheet contains seven problems.
Curated OER
Find the Side of the Triangle
In this geometry worksheet, students investigate the missing side of triangles given the other two sides. There are 5 questions with a solution key.
Curated OER
Easy Worksheet: Types of Triangles
In this types of triangles worksheet, students solve 6 short answer problems. Students identify the type of triangle being described according to side length or angle measure.
Curated OER
Types of Triangles
Students classify triangles by the length of their sides. In this geometry lesson, students use a white board to demonstrate the angles of various triangles. Students construct an equilateral, isosceles, and a scalene triangle.
Curated OER
Geometry and Triangles
In this geometry triangles worksheet, students first determine how many degrees are found in one half and in three-fifths a revolution. Then they find the supplement of the two angles given and the radius of a circle. Students also...
Concord Consortium
Circling Trains
And round and round the park we go! Given a description of an amusement park with the locations of three attractions connected by walkways, learners consider what happens when additional attractions join the mix by doubling the length of...
Curated OER
Triangles
Students identify triangles in the real world and construct their own triangle using drinking straws. They explore abstract triangles and find additional geometric shapes such as trapezoids. Students discuss similar shapes and examine...
Raytheon
Understanding Triangles
In this understanding triangles worksheet, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Curated OER
Review of Trig Ratios
In this trigonometric ratios worksheet, students solve and complete 10 various types of problems. First, they write the degrees listed in radian measure. Then, students find the exact ratios for each equation. They also find the value of...
Curated OER
Triangles
Fourth graders participate in three experiments to gain understanding of triangles. In this triangles lesson, 4th graders use pipe cleaners to create bubble pipes, basketball hoops and bingo cards to display the characteristics of...