Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...
Mt. San Antonio Collage
Properties of a Parallelogram
More than just a activity, the resource provides a thorough guide to navigate through the land of parallelograms. Filled with definitions and theorems, the resource supports learners through problems such as proofs and finding missing...
Math Mammoth
Finding the Area of Rectangles, Parallelograms, and Triangles
For this area of polygons activity, 9th graders solve two area of rectangles, one area of parallelogram, and ten area of triangles problems. The formulas for finding the area of these figures are provided.
Curated OER
Tile Patterns I: Octagons and Squares
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
Centre for Innovation in Mamatics Teaching
Area, Perimeter and Volume
Develop young mathematicians' knowledge of two- and three-dimensional shapes with this geometry workbook. From learning about the classifications of different shapes and figures to calculating their area, perimeter, and volume, this...
Balanced Assessment
Square and Circle
To determine the dimensional change to quadruple the area, class members determine how to increase the dimensions of a square and a circle to increase the perimeter by a given factor. they then calculate the necessary factor to...
California Education Partners
Fun on the Farm
Let imaginations run wild as participants design animal pens. A performance task challenges young mathematicians to determine the perimeter or a missing side length of different animal pens. They then design pens that meet given...
National Council of Teachers of Mathematics
Perplexing Parallelograms
In this geometry worksheet, young mathematicians divide a parallelogram into four, by choosing points along a diagonal. Students calculate the area of each parallelogram and look for any patterns that may emerge. The one-page...
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
Willow Tree
Transformations
How does something go from here to there? Describe it with a transformation. Young mathematicians learn how to translate, reflect, rotate, and dilate an image.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.5 Quadrilaterals
Explore and measure a variety of quadrilaterals.