Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...
Curated OER
Polygons and Diagonals
Students practice measuring the interior angles of given regular polygons and create a formula for finding the measure of th interior angles of any polygon. They determine the relationships between the number of vertices's or sides in a...
Curated OER
Geometers Sketchpad Practice
Students create polygons using geometers sketchpad. In this geometry lesson, students construct the interior angles of polygons and label the different points. They estimate and measure the different parts as they draw conclusion.
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.
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
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...
Corbett Maths
Hexagon Inscribed Within a Circle
Mark off the length of the radius around the circle. Using a compass, the presenter shows how to construct a regular hexagon in a circle. Pupils see how triangles formed in the hexagon are equilateral, allowing for the construction to...
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Curated OER
Artistic Angles
Fifth graders explore angles by using protractors. They recognize, describe and determine the surface area and volume of three-dimensional shapes. Students recognize the right angle, acute angle, obtuse angle and vertex. They identify...
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.
Curated OER
Triangle Conjectures
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson plan, 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...
Curated OER
Quadrilaterals
In this geometry worksheet, 10th graders solve problems with quadrilaterals. They calculate the sum of the angles, find missing angles and identify properties of quadrilaterals. There are 16 questions with an answer key.
Curated OER
Application of Delta-Epsilon Definition of the Limit
Students create a Hexaflexagon using a formula. In this calculus lesson, students apply the definition of delta epsilon as it relates to limit to create a shape using creases. They relate the same rule to triangles and investigate angles.
Curated OER
More on Tessellations
In this tessellations worksheet, 10th graders solve 3 different word problems that include creating various tessellations. First, they group pentagons around a vertex so the angles add up to 360 and determine whether the pentagons can...
Curated OER
Space Tiling with Captain Planet
Fifth graders Apply the symmetry and angle properties of polygons, using symmetry and angle properties of polygons to solve practical problems. They study tessellates and explain why a shape tessellates.
Curated OER
If You Can’t Stand the Heat
Students design and build their own solar cooker. In this math lesson, students determine the relationship between the angles of the sun, reflection and cooking time of the solar cooker. They test their project, collect data and analyze...
Curated OER
Strongest Polygon
Learners define and identify shapes by name. In this geometry lesson plan, students construct, identify and compare polygons based on the number of sides. They classify each shape based on their angle sum theorem.
Curated OER
Inscribed Quadrilaterals and Parallelograms
Learners differentiate between inscribed quadrilaterals and parallelograms. In this geometry lesson, students identify the shaped of the polygons when it is inscribed inside of a circle. They calculate the missing angles of the inscribed...
Curated OER
Application of Delta-Epsilon Definition of the Limit
High schoolers investigate the concept of a Limit and how it is used in a variety of problematic situations. They fold paper to help illustrate how to form equilateral triangles and explain how all the angles are the same. The lesson...
Curated OER
What Is Hyperbolic Geometry?
Ninth graders discuss the concept of hyperbolic geometry. They complete Internet geometry activities and write essays comparing and contrasting hyperbolic geometry to Euclidean geometry.
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence if...
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...
Inside Mathematics
Quadrilaterals
What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...
EngageNY
Review of the Assumptions (part 2)
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...