Hotchalk
Triangle Sum Theorem
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
EngageNY
Angle Sum of a Triangle
Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...
Willow Tree
Angle Sum Property of Triangles
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.
EngageNY
More on the Angles of a Triangle
Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...
Curated OER
Properties and Attributes of Polygons
In this geometry instructional activity, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior...
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
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.
Curated OER
Properties of Angles, Lines, and Triangles
In this properties of angles, lines and triangles instructional activity, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties...
Willow Tree
The Pythagorean Theorem
There isn't a more popular geometry formula than the Pythagorean Theorem! Learners understand the special side relationships in a right triangle. They use the Pythagorean Theorem to find missing sides and to solve problems. They begin...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete practice...
Mathed Up!
Angles: Parallel Lines
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the problems.
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...
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
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
Polygons
In this polygons worksheet, 10th graders identify and define both a polygon and a convex polygon and then, they apply two theorems that involve the interior and exterior angles of a convex polygon. First, they find the sum of the...
Curated OER
Triangle Exterior Angles Theorem
Students identify the measure of missing exterior angles. In this geometry lesson,students define and apply the exterior angle theorem to solve problems. They use Cabri software to create different angles and make investigations.
Flipped Math
Unit 3 Review: Parallell and Perpendicular Lines
Learners watch a quick review on the Parallel and Perpendicular Lines unit. The pupils work through ten review problems ranging from identifying types of angles formed by parallel lines and transversals to writing equations of parallel...
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.
Charleston School District
Pre-Test Unit 2: Similar and Congruent
A pre-test contains questions about transformations that lead to congruent and similar images. It also covers angle relationships associated with triangles and parallel lines intersected by a transversal.
Curated OER
Proving Quadrilaterals
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
Pythagorean Theorem
Students investigate the concept of the Pythagorean Theorem. After conducting independent practice to find the hypotenuse of a triangle, they work with the teacher using examples in the lesson plan. The direct instruction is delivered...
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...
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
Polygons Multiple Choice
In this geometry worksheet, students identify the interior and exterior angles using the angle sum theorem. They identify and solve quadrilaterals using properties of quadrilaterals. There are 12 questions with an answer key.