Interactive
Noetic Learning

Kinds of Triangles (Online Interactive)

For Students 3rd - 4th
In this triangles learning exercise, students analyze pictures of four triangles. For each triangle, students mark if it is acute, obtuse, or right.
Activity
1
1
Curated OER

Mt. Whitney to Death Valley

For Teachers 9th - 12th Standards
This is an intriguing problem that brings together real-world data, technology, and mathematical problem solving. If visibility wasn't an issue, could you see from the highest point in the lower 48 states, Mt. Whitney, to the lowest...
Lesson Plan
Curated OER

Triangle Congruence

For Teachers 9th - 11th
Students use web applet to create congruent triangles. In this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
Lesson Plan
Curated OER

Human Geometry Book

For Teachers 3rd - 5th
Students investigate geometric shapes. In this geometry lesson, students read the book The Greedy Triangle and define the shapes mentioned in the book. Students make the shapes by using their bodies.
Lesson Plan
Curated OER

Types of Triangles

For Teachers 1st - 2nd
Young scholars classify triangles by the length of their sides. In this geometry lesson, students use a white board to demonstrate the angles of various triangles. Young scholars construct an equilateral, isosceles, and a scalene triangle.
Lesson Plan
Curated OER

Obtuse Triangles

For Teachers 4th
Fourth graders explore obtuse triangles. In this geometry instructional activity, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.
Lesson Plan
Curated OER

Altitude Locator

For Teachers 9th - 12th
Students use protractors, strings, and straws to construct a device used to determine the height of tall objects. In this applied geometry lesson, students use common objects to construct a tangent height guide. They use principles of...
Lesson Plan
Curated OER

Roll It! Creating an Entrance Ramp

For Teachers 9th - 12th
High schoolers explore the concept of triangles.  In this triangles lesson, students are to propose a plan for a ramp at their school.  High schoolers use the Pythagorean Theorem and trigonometry to determine the length,...
Lesson Plan
Curated OER

Triangle Puzzler

For Teachers 5th - 8th
Students are introduced to some basic concepts of geometry. They explain that the definition of a triangle is a figure with three sides, three angles, and three points. Triangles can be named by using three points in their correct sequence.
Worksheet
Curated OER

Triangles

For Students 3rd - 4th
In this triangles worksheet, students identify 3 triangles by the length of their sides and 3 triangles according to their internal angles.
Lesson Plan
Curated OER

Triangle Attributes and Measures

For Teachers 7th
Seventh graders explore the concept of triangles. In this triangles activity, 7th graders sort triangles according to various attributes such as acute, obtuse, isosceles, or equilateral. Students find the area and perimeter of triangles.
Lesson Plan
Curated OER

Equilateral Triangles

For Teachers 4th - 5th
Learners examine the attribute of equilateral triangles. In this equilateral triangle lesson, students examine a number of paper triangles to determine how they are classified. They determine how triangles are depicted in Navajo rugs.
Lesson Plan
Curated OER

Let's Explore the World of Triangles and Quadrilaterals!

For Teachers 2nd
Second graders explore the features of triangles and quadrilaterals. In this lesson on triangles and quadrilaterals, 2nd graders rotate with their group to five different activities all exploring a different aspect of geometry.
Worksheet
Curated OER

Family Activity: Triangles and Quadrilaterals

For Students 6th - 8th
In this triangles and quadrilaterals worksheet, middle schoolers solve 7 short answer problems. Students find objects around the house that are constructed from triangles, parallelograms, trapezoids, squares, rectangles. Middle schoolers...
Worksheet
Curated OER

Perimeter and Area

For Students 3rd - 8th
Use this perimeter and area instructional activity to have learners find the perimeter and area of shapes with right angles. They complete a total of nine problems.
Worksheet
Curated OER

Geometry and Measurement Pre-Test

For Students 6th - 10th
Use this comprehensive pre-instruction assessment tool to focus your teaching where your class needs it most. Multiple choice questions assess your budding geometers' conceptual and vocabulary knowledge, but they do not solve any...
Lesson Plan
Curated OER

Identify triangles

For Teachers 9th - 10th
Students explore triangles. In this geometry lesson, students will create note cards with pictorial depictions of right, acute,obtuse, scalene, isosceles, equilateral and equiangular triangles. Students will verbally describe each type...
Lesson Plan
Curated OER

Isosceles Triangles

For Teachers K - 2nd
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...
Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th
Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.
Lesson Plan
Curated OER

Review Geometry - Week 8 (Triangles)

For Teachers 11th - 12th
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
Lesson Plan
Curated OER

Triangle Inequality Theorem

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

Similar Triangles - Applied Problems

For Teachers 9th - 12th
Students differentiate between similar and congruent triangles. For this geometry lesson, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
Lesson Plan
Curated OER

Exterior and Interior Angles of Triangles

For Teachers 10th
Tenth graders explore the exterior and interior angles of triangles. They use a theorem in order to prove a theorem about all polygons. Students use the theorem and its applications to find the angles of different types of triangles.
Worksheet
Curated OER

Using Algebraic Equations in Geometry Problems

For Students 6th
In this using algebraic equations in geometry problems worksheet, 6th graders write an equation to solve each addition problem about geometry, then find the solution.