Illustrative Mathematics
Illustrative Mathematics: G Srt Folding a Square Into Thirds
The goal of this task is to apply knowledge about similar triangles in order to understand an origami construction: trisection of the side of a square. Aligns with G-SRT.B.5.
Illustrative Mathematics
Illustrative Mathematics: G Srt Bank Shot
This task asks students to use similarity to solve a pool table problem. Students must use the fact from physics that when an object bounces off of a wall, the angle of incidence equals the angle of reflection. Aligns with G-SRT.B.5.
Illustrative Mathematics
Illustrative Mathematics: G Gpe, G Srt Slope Criterion for Perpendicular Lines
The goal of this task is to use similar triangles to establish the slope criterion for perpendicular lines. Aligns with HSG-GPE.B.5 and HSG-SRT.B.5.
Illustrative Mathematics
Illustrative Mathematics: G Srt Tangent Line to Two Circles
The purpose of this task is to use similar triangles and setting up a proportion in order to calculate a side length. Aligns with G-SRT.B.5.
Illustrative Mathematics
Illustrative Mathematics: G Srt Extensions, Bisections, Dissections in Rectangle
For this task, learners must draw a diagram from a verbal description and use their understanding of similar triangles to find the area of a quadrilateral. Aligns with G-SRT.B.5.
Illustrative Mathematics
Illustrative Mathematics: G Gpe, G Srt Finding Triangle Coordinates
Given a picture of a triangle on a coordinate grid, students are asked to find the coordinates of points which divide line segments in a given ratio. Aligns with G-GPE.B.6 and G-SRT.B.5.
ClassFlow
Class Flow: Angles in Geometry
[Free Registration/Login Required] This flipchart is a look at angles in geometry. Drawing, labeling, measuring, special angles: (right, straight, acute, obtuse) and congruence.
CK-12 Foundation
Ck 12: Interactive Middle School Math 8 for Ccss
A complete CCSS Grade 8 Mathematics course that includes interactives in every lesson, plus videos, hands-on activities, and questions with immediate feedback. Every lesson also has specifically chosen 'Related Modalities' that teach the...
Cuemath
Cuemath: Median of a Triangle
This lesson explores the equation of the median of a triangle formula, sum of medians of a triangle, altitude of a triangle, median of equilateral triangle formula, and median of a triangle definition while discovering the interesting...
National Council of Teachers of Mathematics
Nctm: Figure This: Math Challenges for Families
Students, teachers, and parents alike will enjoy this challenging math site. It contains a clever brain teaser section plus creative problems related to algebra, geometry, measurement, numbers, statistics, and probability. A Spanish...
University of Saskatchewan (Canada)
University of Saskatchewan: Triangles
This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.
Texas Instruments
Texas Instruments: Copying an Angle
Explore relationships (including congruence and similarity) among classes of two- and three-dimensional geometric objects, make and test conjectures about them, and solve problems involving them.
Alabama Learning Exchange
Alex: Tan Ii
The Chinese character mark for Tan II (pronounced she-tow-bah) is the second of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students...
Alabama Learning Exchange
Alex: "Tan"
The Chinese character mark formerly known as "Tan" is the first of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students will be able...
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg How Far Is the Horizon?
Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...
Illustrative Mathematics
Illustrative Mathematics: G Srt Joining Two Midpoints of Sides of a Triangle
In this task, students must prove that angles and triangles are congruent and that a parallel line passes through the midpoints of two sides of the larger triangle. Aligns with G-SRT.B.4.
National Council of Teachers of Mathematics
Nctm: Illuminations: Making Triangles
Understand the mathematical meaning of a triangle and the idea of congruence, or sameness, in geometry.
Other
Nearpod: Introduction to Geometric Transformations
In this lesson plan, students will learn how to describe and identify reflections, rotations, translations, and dilations.
ClassFlow
Class Flow: Transformations
[Free Registration/Login Required] In this flipchart, students apply multiple transformations to create congruent and similar figures in any or all of the four quadrants. Students apply their geometric sense by using multiple...
Mocomi & Anibrain Digital Technologies
Mocomi: Types of Triangles
Explore the different types of triangles and other properties.
Better Lesson
Better Lesson: Geometric Transformations
Search for common core lesson plans on geometric transformations.