Illustrative Mathematics
Find the Angle
This a fun problem for young geometers to play with while gaining important insight into deductive reasoning. Some will find the answers very quickly, others might take a less direct path, but all will use their knowledge of the sum of...
Mathematics Assessment Project
Identifying Similar Triangles
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...
Curated OER
Exploring Characteristics of Triangles
Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...
Lone Star College
Geometry Worksheet II
Young geometers get practice with the algebra of angles in an extensive skills practice activity. Supplementary, complementary, and vertical angle relationships are used, along with parallel lines cut by a transversal and angle sum...
Curated OER
Triangle Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. For this geometry lesson, students 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
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 Theorems Investigation
Students estimate and measure triangles. In this geometry lesson, 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.
Math Mammoth
Triangles 1
In this triangles worksheet, students measure and calculate the measurements of eight triangles, their sums and classify the triangles as acute, obtuse or right.
University of Utah
Geometry: Angles, Triangles, and Distance
The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.
Curated OER
Sum of Interior/Exterior Angles with Wilbur
Young scholars identify the interior and exterior measures of polygons. In this geometry lesson plan, students identify the formula for interior angles of polygons. They differentiate between triangular and polygons angles.
Curated OER
Interior Angles of Regular Polygons
Students investigate the interior angles of a triangle. In this geometry lesson, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.
Houghton Mifflin Harcourt
Unit 5 Math Vocabulary Cards (Grade 6)
Acute angle, line of symmetry, and vertex are a few terms you'll find in a set of 90 flashcards designed to reinforce math vocabulary. Included in the set are two types of cards; a word card printed in bold font, and a...
Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders discover the patterns of sums of polygon angles. In this math lesson, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.
Curated OER
Investigation - Adrienne's Pattern Block Angles
Fifth graders investigate possible solutions to a word problem. They explore properties of polygons and right angles. Students demonstrate proper angle measurement. Students discover patterns.
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Learners discover the sum of the interior and exterior angles of several polygons. For this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons....
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...
Curated OER
The Sum of All Angles
Young scholars add up the different angles using the angle addition postulate. In this geometry instructional activity, students differentiate between interior and exterior angles. They calculate the different angles for triangles and...
Curated OER
Geometric Properties
Students find triangular angles using the angle theorem. For this geometry lesson, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
Curated OER
Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson plan, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make...
Math Mammoth
Construct Line Segments and Angles
In this math worksheet, learners are asked to used a compass and straight edge to construct copies of shapes, angles and line segments.
Beacon Learning Center
Angles and Algebra
Learners calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Curated OER
Exterior and Interior Angles of Triangles
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.
Utah Education Network (UEN)
Geometric Figures and Scale Drawings
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
Curated OER
Triangle Sum Theorem
Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two...