Curated OER
Geometry Scavenger Hunt
Students use the digital camera, identify geometric shapes (in nature as well as man-made), and gain a better understanding of geometric vocabulary. They search for and recognize geometric shapes in unusual settings
Curated OER
Equation of a Circle
Learners write the equation of a circle. For this geometry lesson, students check the solution of a coordinate pair by evaluating them. They graph the circle given the equation and radius.
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Virginia Department of Education
Similar Triangles
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
EngageNY
Representing Reflections with Transformations
In the 16th lesson in the series of 32 the class uses the concept of complex multiplication to build a transformation in order to reflect across a given line in the complex plane. The lesson breaks the process of reflecting across a line...
Curated OER
Cracks on the Walls
Learners observe the cracks in school walls and pavements. In this geometry lesson, students explore the factors to be considered before building a structure. They complete a graphing and calculation worksheet after the lesson.
EngageNY
Are All Parabolas Similar?
Congruence and similarity apply to functions as well as polygons. Learners examine the effects of transformations on the shape of parabolas. They determine the transformation(s) that produce similar and congruent functions.
Alabama Learning Exchange
Alex: Geometry City
This lesson plan reviews transformations in the coordinate plane while mimicking real-world planning skills. It gives an assessment and ideas for remediation, extention as well as ways to manage behavior problems and reluctant learners.