Curated OER
Relationship between Exterior and Remote Interior Angles in a Triangle
In this triangle activity set, 9th graders find the relationship between the exterior and remote interior angles in triangles. They determine the formula, and apply it in 15 problems. They use a compass as needed to measure angles.
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons. Students...
Curated OER
Measuring Angles in a Quadrilateral
High schoolers explore quadrilaterals in this geometry lesson. They will draw a quadrilateral, measure the angles, and find the sum of the measures of the interior angles using Cabri Jr. The interactive capabilities of Cabri Jr. allow...
Curated OER
Angles in Polygons
In this angles in polygons activity, students determine the value of a missing angle measure. They find the value of interior angles and exterior angles. Polygons include triangles, quadrilaterals, pentagons, and hexagons. This...
Curated OER
Triangle Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. In 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
Interior and Exterior Angles of Polygons
In this angles of polygons worksheet, 10th graders solve and complete 18 different problems that include determining various interior and exterior angles. First, they determine the measure of various angles described in the first half of...
Curated OER
Properties of Angles, Lines, and Triangles
For this properties of angles, lines and triangles worksheet, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties and theorems...
Virginia Department of Education
High School Mathematics Geometry Vocabulary Word Wall Cards
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
Curated OER
Geometric Properties
Young scholars 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
Geometry Journal: Isosceles Triangles
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
Curated OER
Exploring Geometry on the Sphere
In this geometry worksheet, students define important vocabulary dealing with circles. They measure cricles to the nearest degree. There are 11 word problems to be solved.
EngageNY
Geometry Module 5: Mid-Module Assessment
How can you formally assess understanding of circle concepts? Pupils take a mid-module assessment containing five questions, each with multiple parts.
Curated OER
Polygons - Sum of Interior Angles
For this polygon worksheet, students determine the sum of the interior angles of a figure. Given the sum of the interior angles, they determine the number of sides of a polygon and the measure of one central angle. This one-page...
Curated OER
Triangle Angle-Sum Theorem
In this polygons activity, 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.
Curated OER
Polygon Sum Conjecture
In this geometry worksheet, 10th graders identify the missing angles using the polygons sum conjecture. They measure exterior and interior angles using their angle theorems. There are 63 problems.
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 lesson provides an...
Curated OER
Angles of a Triangle
Learners explore the measures of the angles of a triangle in this geometry lesson plan. They use Cabri Jr. to investigate the sum of the measures of the interior angles of a triangle, and examine the relationships between the interior...
Curated OER
Sum of Exterior Angles of Polygons
Have fun calculating angles for different polygons. The class differentiate the relationship between the interior and exterior angles of polygons. They discuss linear pair as it related the polygons and their angles. This is done as they...
Curated OER
Angles and Arcs
Students identify the relationship between angles and arcs. In this geometry lesson, students rotate and move the circle around to create different arcs on the TI-Navigator. They differentiate between major and minor arcs.
Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders discover the patterns of sums of polygon angles. In this math lesson plan, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.
Curated OER
Christmas Tree Angles
In this angles worksheet, students measure angles to make triangles and cut them out to make a Christmas tree. Students draw and cut 5 triangles to make their tree.
Mathematics Vision Project
Module 3: Geometric Figures
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
Virginia Department of Education
How Many Triangles?
Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...