Lesson Plan
Curated OER

Interior Angles of Regular Polygons

For Teachers 9th - 12th Standards
Students investigate the interior angles of a triangle. In this geometry activity, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.
Worksheet
Curated OER

Triangle Fundamentals

For Students 8th - 12th
In this geometry worksheet, students observe a triangle marked with three angles and are given two measures to find the missing third measure. A second diagram is given with six angles. There are 20 questions.
Worksheet
Math Mammoth

Classify The Triangles

For Students 6th - 8th
In this math worksheet, students measure all the angles in these triangles. They also calculate the sum of the angles and classify the triangles.
Lesson Plan
Curated OER

Geometric Properties

For Teachers 9th - 12th
Students find triangular angles using the angle theorem. In this geometry lesson, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
Worksheet
Curated OER

Angles

For Students 6th - 8th
In this math learning exercise, students measure a series of angles. Then they measure the angles in the triangles and determine the sum of the angles.
Worksheet
Curated OER

Shapes and Designs

For Students 10th
In this shapes and designs worksheet, 10th graders solve and complete 6 different types of problems. First, they fill in the first two columns of the table show with their shapes. Then, students measure the interior angles of each...
Lesson Plan
Curated OER

Patterns in the Sums of Polygon Angles

For Teachers 6th
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.
Lesson Plan
Curated OER

Tile Patterns I: Octagons and Squares

For Teachers 7th - 9th Standards
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
Lesson Plan
EngageNY

Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams

For Teachers 9th - 12th Standards
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
Lesson Plan
Curated OER

The Sum of All Angles

For Teachers 7th - 10th
Students add up the different angles using the angle addition postulate. In this geometry lesson plan, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show...
Lesson Plan
Curated OER

Sum of Interior/Exterior Angles with Wilbur

For Teachers 7th - 10th
Learners identify the interior and exterior measures of polygons. In this geometry activity, students identify the formula for interior angles of polygons. They differentiate between triangular and polygons angles.
Organizer
Curated OER

Triangle Angle-Sum Theorem

For Students 5th - 8th
In this polygons worksheet, students fill out a graphic organizer about the name of the polygon, the number of sides, the angle sums, and more. Students complete this for 5 polygons.
Handout
Del Mar College

Formulas for Elementary and Intermediate Algebra

For Students 6th - 9th Standards
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more. 
Interactive
1
1
GeoGebra

Conjectures and Proof

For Students 9th - 12th Standards
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
Performance
Radford University

How Much is in There? A Polygon Investigation

For Teachers 6th - 8th Standards
Try to find the triangles in various polygons. An investigation has learners develop a formula for the sum of the measures of the interior angles of a polygon. They use manipulatives to partition each polygon into triangles, then...
Assessment
Concord Consortium

Always, Sometimes, Never

For Students 9th - 10th Standards
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...
Worksheet
Geometry Accelerated

Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
Lesson Plan
Curated OER

Twenty-Five Measures of the Angles of a Triangle Problems

For Teachers 9th - 10th
In this triangle worksheet, students calculate the measures of the angles or the sums of the measures of the angles in twenty-five triangle problems and hands-on activities.  The solutions are provided.
Worksheet
Math Mammoth

Triangles 1

For Students 5th - 9th
In this triangles worksheet, students measure and calculate the measurements of eight triangles, their sums and classify the triangles as acute, obtuse or right.
Lesson Plan
Curated OER

Triangle Classificaition with Geometer's Sketchpad.

For Teachers 7th - 12th
Students 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.
Worksheet
Math Mammoth

Construct Line Segments and Angles

For Students 6th - 7th
In this math learning exercise, learners are asked to used a compass and straight edge to construct copies of shapes, angles and line segments.
Worksheet
Curated OER

Triangle worksheets

For Students 10th
In this geometry activity, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
Lesson Plan
Beacon Learning Center

Angles and Algebra

For Teachers 6th - 8th
Students calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Printables
1
1
Houghton Mifflin Harcourt

Unit 5 Math Vocabulary Cards (Grade 6)

For Students 6th Standards
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...