EngageNY
The Geometric Effect of Some Complex Arithmetic 2
The 10th activity in a series of 32, continues with the geometry of arithmetic of complex numbers focusing on multiplication. Class members find the effects of multiplying a complex number by a real number, an imaginary number, and...
Curated OER
A Geometry Worksheet - Similar Triangles
In this similar triangles instructional activity, students find the scale factor of 6 sets of similar triangles. Students find the scale factor of two similar triangles given a sketch with measurements. Students use proportions to find a...
Virginia Department of Education
Transformations
Geometry in life-sized dimensions! Using enlarged graph paper, pupils perform a series of transformations. By recording the initial and final placement of the images, they are able to analyze the patterns in the coordinates during a...
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
Informal Proof of AA Criterion for Similarity
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
Curated OER
Triangles
In this triangles worksheet, 10th graders solve and graph 8 different problems that include various transformations. First, they write a rule for the composition of a dilation of a scale factor. Then, students determine whether a graphed...
Curated OER
Reflections over Two Lines & Dilations
Students create reflections over two lines. In this reflections worksheet, students compare and contrast reflections over parallel and intersecting lines. They dilate figures and investigate the effect of the dilation using measurement...
EngageNY
General Pyramids and Cones and Their Cross-Sections
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...
Virginia Department of Education
Rotation
Rotate this resource into your lesson plans. Scholars rotate polygons in the coordinate plane by multiples of 90 degrees. They then compare the original and new figures to develop conjectures about coordinate points after rotations.
Mathematics Assessment Project
Evaluating Statements About Enlargements
Double, toil ,and double linear dimensions. Learners first complete an assessment investigating how doubling linear dimensions affects the area of pizzas and the volume of popcorn containers. They then complete an activity investigating...
Curated OER
Angle Exploration and Classification
Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.
Curated OER
Geometric Transformations
Learners examine images and preimages of a mapping and identify isometry. They view images by M.C. Escher, observe teacher demonstrations, and create a translation image, a rotation image, and a dilation.
EngageNY
Trigonometry and Complex Numbers
Complex numbers were first represented on the complex plane, now they are being represented using sine and cosine. Introduce the class to the polar form of a complex number with the 13th part of a 32-part series that defines the argument...
Curated OER
Geometry Scavenger Hunt
Young scholars 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
Transformations Homework
In this geometry worksheet, students transform a coordinate based on a reflection, translation, or dilation in order to obtain the image. There are 12 questions.
EngageNY
What Are Similarity Transformations, and Why Do We Need Them?
It's time for your young artists to shine! Learners examine images to determine possible similarity transformations. They then provide a sequence of transformations that map one image to the next, or give an explanation why it is not...
Curated OER
Exploring Quadratic Data with Transformation Graphing
Using a data collection device to collect data regarding a bouncing ball, students use various features on graphing calculators to experiment with the parameters of the vertex form of the parabola and their effect on the shape of the...
Curated OER
Exploring Quadratic Data : Transformation Graphing
High schoolers analyze the vertex form of a parabola and find an approximate fit of a model. They explain the quadratic parabola function and its properties by developing quadratic models. They use translation and dilation to change the...
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...
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
EngageNY
The Geometric Effect of Some Complex Arithmetic 1
Translating complex numbers is as simple as adding 1, 2, 3. In the ninth lesson in a 32-part series, the class takes a deeper look at the geometric effect of adding and subtracting complex numbers. The resource leads pupils into what it...
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
Dilations of 2 and 3 dimentional figures and their effect on area, surface area, and volume.
Seventh graders investigate the area and volume of 2D and 3D figures. In this geometry instructional activity, 7th graders create a storyboard explaining their knowledge of 2D and 3D shapes. They analyze their data and interpret their...
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...