Concord Consortium
Triangles: Angle Space
Three angles in a triangle, three-dimensional space, it all seems connected somehow. Given several different triangles, pupils use the three angles of the triangle as coordinates to plot points in three-dimensional space. They explore...
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 Triangles
Students investigate triangles. In this shapes geometry lesson, students define and state the attributes for equilateral, scalene, and isosceles triangles. Students locate the prefix "tri" in a variety of words and make connections with...
Curated OER
Triangles
In this triangles learning exercise, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of 3...
Curated OER
Classifying Triangles
In this classifying triangles instructional activity, 6th graders write the type of triangle, acute, right or obtuse, for 9 pictures of triangles, answers included.
Mathematics Vision Project
Geometric Figures
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
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...
Curated OER
Identify Angles
In this angles practice learning exercise, students respond to 4 questions that require them to identify the pictured angles as acute, right, or obtuse triangles.
Curated OER
The Truth About Triangles And Proofs
Learners engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance 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...
Curated OER
Drawing Triangles
In this drawing triangles worksheet, 6th graders read the dimensions of four triangles, given the length or the angle, identify the type of triangle and draw it.
Curated OER
Similar Triangles - Applied Problems
Students differentiate between similar and congruent triangles. In this geometry instructional activity, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles.
Concord Consortium
Always, Sometimes, Never
Do your learners always, sometimes, or never remember the properties of the segments in triangles? Get that number closer to always with a creative lesson analyzing all four segments. Scholars consider a statement about one of the...
Curated OER
Nested Similar Triangles
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
Curated OER
Measuring Angles in a Triangle
High schoolers investigate the sum of the measures of the angles of a triangle. They draw a triangle and measure the interior angles. Using Cabri Jr., learners find the sum of the measures of the interior angles. The instructional...
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.
Curated OER
Inscribing a Circle in a Triangle
Pupils investigate inscribing a circle in a triangle. They use Cabri Jr. to draw a triangle, locate the incenter, and use the distance from the incenter to a side of the triangle to inscribe a circle. The dynamic nature of the geometry...
Curated OER
Midsegments of a Triangle
Learners analyze midsegments of triangles in this instructional activity. They use Cabri Jr. software to observe the relationships between interior angles and midsegments of triangles. Specific instructions for creating this...
Curated OER
Right Triangles
In this right triangles worksheet, 10th graders solve and complete 12 various types of problems. First, they solve for x given each of the right triangles shown. Then, students determine the length of the shorter diagonal given the...
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 Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. For this geometry lesson, young scholars identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides around to...
Curated OER
Triangle Classificaition with Geometer's Sketchpad.
Learners use Geometer's Sketchpad to draw triangles and explore the classificaiton of each using the mearsures of interior angles and the lengths of the sides.
Curated OER
Right Triangles
For this right triangles worksheet, 10th graders solve and complete 5 different types of problems. First, they solve each of the right triangles shown and express each answer correct to two decimal places. Then students find the...