EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
Concord Consortium
Isosceles Triangle Spaces
How many different types of triangles can your class name? A discovery lesson guides learners through an exploration of the different triangle types and the relationships between their angles and sides. Using coordinate geometry,...
Curated OER
Isosceles Triangles
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
Curated OER
Triangle Inequality Theorem
Young scholars use the inequality theorem to solve triangles and their properties. In this geometry instructional activity, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary...
Concord Consortium
Divisions
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
Beacon Learning Center
The Fun Polygon
Junior geometers use hands-on manipulatives to explore and describe the properties and attributes of a fundamental polygon, the triangle. They learn different kinds of angles and their measurements. This well-written lesson plan provides...
Curated OER
Geometry and Measurement
Students view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Students use pegboards and string to create more...
Curated OER
An Introduction to Quadrilaterals
Students explore different types of quadrilaterals. Students define the terminology used with quadrilaterals. They create particular quadrilaterals based on specific characteristics of the quadrilaterals using an online tool.