Lesson Plan
Mathematics Assessment Project

Identifying Similar Triangles

For Teachers 7th - 9th Standards
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,...
Lesson Plan
Curated OER

Triangle Exterior Angles Theorem

For Teachers 7th - 9th
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.
Lesson Plan
EngageNY

More on the Angles of a Triangle

For Students 8th Standards
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...
Lesson Plan
Curated OER

Interior and Exterior Angles of Polygons

For Teachers 9th - 10th
Pupils identify interior and exterior angles of polygons. In this geometry lesson plan, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.
Lesson Plan
Curated OER

Geometric Properties

For Teachers 9th - 12th
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.
Lesson Plan
Curated OER

Triangle Inequality Theorems Investigation

For Teachers 9th - 10th
Students estimate and measure triangles. In this geometry lesson plan, 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.
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.
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

Strongest Polygon

For Teachers 9th - 12th
Students define and identify shapes by name. In this geometry instructional activity, students construct, identify and compare polygons based on the number of sides. They classify each shape based on their angle sum theorem.
Lesson Plan
Curated OER

Triangle Conjectures

For Teachers 10th
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. 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 angles are formed by...