Curated OER
Obtuse Triangles
Fourth graders explore obtuse triangles. In this geometry lesson plan, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.
Texas Instruments
Identifying a Triangle by its Sides and Angles
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
Curated OER
Toothpick Triangles
Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...
Curated OER
Geometric Properties
Learners 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
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...
Curated OER
Review of Triangles
Students investigate the Pythagorean Theorem. For this geometry lesson, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
Curated OER
Triangle Classification
Students classify different types of triangles. For this geometry lesson, students identify and use properties of triangles. They differentiate between isosceles and equilateral triangles.
Curated OER
Angles in Triangles
Eighth graders translate word problems using mathematical ideas. In this geometry lesson, 8th graders identify angles of triangles using equations and the triangle sum theorem. They create angles with a protractor and straight edge.
Curated OER
Triangle Side Lengths and Angles Measures
Students identify missing sides and angles. In this geometry lesson, students use triangular theorems to identify the missing sides. They use the Pythagorean Theorem to find the different ratios of each side.
Curated OER
Angle-Side Relationships
Students calculate the different sides and angles of a triangle. In this geometry lesson, students use triangular properties to define the relationship between two triangle. They identify missing angles using the interior angle theorem.
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
Pythagorean Theorem
Students find the different ratios of a triangle. In this geometry instructional activity, students use the Pythagorean Theorem to solve for missing sides and angles on a right triangle. They use a robot to create a right triangle.
Curated OER
Pythagorean Theorem
Students explore the history of Pythagoras and his contributions to mathematics. In this middle school geometry instructional activity, students use one inch tiles to investigate the Pythagorean Theorem and to find the length of the...
Curated OER
Pythagorean Theorem
Students investigate the properties and idea of the Pythagorean Theorem. In this algebra lesson, students identify the different parts of a right triangle and relate it to the Pythagorean Theorem. They do a robotic experiment to...
Curated OER
The Sum of All Angles
Students add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...