This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Each shape below has a line of symmetry. Draw a line of symmetry for each shape. Not every shape has an line of symmetry. Which of the four shapes belo...

This 20-day module introduces points, lines, line segments, rays, and angles, as well as the relationships between them. Students construct, recognize, and define these geometric objects before using their new knowledge and understanding to classify figures and solve problems. With angle measure playing a key role in their work throughout the module, students learn how to create and measure angles, as well as create and solve equations to find unknown angle measures. In these problems, where the unknown angle is represented by a letter, students explore both measuring the unknown angle with a protractor and reasoning through the solving of an equation. Through decomposition and composition activities as well as an exploration of symmetry, students recognize specific attributes present in two-dimensional figures. They further develop their understanding of these attributes as they classify two-dimensional figures based on them.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

This is an instructional task that gives students a chance to reason about lines of symmetry and discover that a circle has an an infinite number of lines of symmetry. Even though the concept of an infinite number of lines is fairly abstract, fourth graders can understand infinity in an informal way.

This task provides students a chance to experiment with reflections of the plane and their impact on specific types of quadrilaterals. It is both interesting and important that these types of quadrilaterals can be distinguished by their lines of symmetry.

This task is intended for instruction, providing the students with a chance to experiment with physical models of triangles, gaining spatial intuition by executing reflections.

(Nota: Esta es una traducción de un recurso educativo abierto creado por el Departamento de Educación del Estado de Nueva York (NYSED) como parte del proyecto "EngageNY" en 2013. Aunque el recurso real fue traducido por personas, la siguiente descripción se tradujo del inglés original usando Google Translate para ayudar a los usuarios potenciales a decidir si se adapta a sus necesidades y puede contener errores gramaticales o lingüísticos. La descripción original en inglés también se proporciona a continuación.)

Este módulo de 20 días introduce puntos, líneas, segmentos de línea, rayos y ángulos, así como las relaciones entre ellos. Los estudiantes construyen, reconocen y definen estos objetos geométricos antes de usar su nuevo conocimiento y comprensión para clasificar las cifras y resolver problemas. Con la medida de ángulo que juega un papel clave en su trabajo a lo largo del módulo, los estudiantes aprenden cómo crear y medir ángulos, así como crear y resolver ecuaciones para encontrar medidas de ángulo desconocidas. En estos problemas, donde el ángulo desconocido está representado por una letra, los estudiantes exploran ambos midiendo el ángulo desconocido con un protractor y razonamiento a través de la resolución de una ecuación. A través de actividades de descomposición y composición, así como una exploración de la simetría, los estudiantes reconocen atributos específicos presentes en figuras bidimensionales. Desarrollan su comprensión de estos atributos a medida que clasifican las figuras bidimensionales basadas en ellas.

Encuentre el resto de los recursos matemáticos de Engageny en https://archive.org/details/engageny-mathematics.

English Description:
This 20-day module introduces points, lines, line segments, rays, and angles, as well as the relationships between them. Students construct, recognize, and define these geometric objects before using their new knowledge and understanding to classify figures and solve problems. With angle measure playing a key role in their work throughout the module, students learn how to create and measure angles, as well as create and solve equations to find unknown angle measures. In these problems, where the unknown angle is represented by a letter, students explore both measuring the unknown angle with a protractor and reasoning through the solving of an equation. Through decomposition and composition activities as well as an exploration of symmetry, students recognize specific attributes present in two-dimensional figures. They further develop their understanding of these attributes as they classify two-dimensional figures based on them.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

The intent of clarifying statements is to provide additional guidance for educators to communicate the intent of the standard to support the future development of curricular resources and assessments aligned to the 2021 math standards.  Clarifying statements can be in the form of succinct sentences or paragraphs that attend to one of four types of clarifications: (1) Student Experiences; (2) Examples; (3) Boundaries; and (4) Connection to Math Practices.

In this video segment from Cyberchase, a plant expert shows Bianca the patterns and symmetry found in nature.

Students learn about the history of tangrams.  They will learn about each piece in the tangram puzzle and analyze the shapes to complete geometric puzzles and mathematics problems.