Objectives (5 - 10 minutes)

1. Recognize plane figures in everyday life: The teacher must guide the students to identify and name the plane geometric shapes (such as rectangles, squares, triangles, circles, etc.) in their environment, highlighting the presence of these shapes in everyday objects.

2. Understand the properties of plane figures: The teacher must explain the characteristics and properties of plane figures, such as number of sides, internal and external angles, axes of symmetry, and other attributes that define them.

3. Apply the knowledge about plane figures in practical situations: The teacher must propose problem situations that involve the recognition and use of the properties of plane figures, encouraging students to apply the knowledge acquired in a practical and contextualized way.

Secondary objectives

• Develop logical-mathematical thinking: Through solving problems involving plane figures, students will be encouraged to develop logical and deductive thinking skills.

• Stimulate spatial perception: The study of plane figures contributes to the perception and understanding of space, essential skills in various areas of knowledge.

Introduction (10 - 15 minutes)

1. Review of previous contents: The teacher should begin the class by reviewing the concepts of plane geometry already studied, such as points, lines, line segments, half-lines, polygons, angles, among others. This review can be done through direct questions to the students or using visual resources such as geometric figures projected on the board.

2. Presentation of problem situations: To arouse students' interest and contextualize the subject, the teacher can present two problem situations. The first one could be: "How can we calculate the area of a football field, knowing that it has the shape of a rectangle?" The second one: "When building a house, why is it important to know the characteristics and properties of plane figures?" These questions should be discussed with the class, and the possible answers should be written on the board.

3. Contextualization of the importance of the subject: The teacher should then contextualize the importance of plane figures, explaining that they are present in our daily lives in several ways, from the shape of the objects we use to architectural constructions. In addition, knowledge about plane figures is essential for studying areas, perimeters, volumes, among other mathematical concepts.

4. Introduction to the topic: To introduce the topic, the teacher can tell the story of how the ancient Egyptians used knowledge of plane geometry to build their pyramids. He can also mention how plane geometry is essential for constructing maps, aircraft, buildings, and even in art, music, and nature. These curiosities serve to arouse students' curiosity and show the relevance of the subject.

Development (20 - 25 minutes)

1. Presentation of the theory (10 - 15 minutes):

   • Definition of Plane Figures (3 - 5 minutes): The teacher should begin the explanation by defining what plane figures are, emphasizing that they are two-dimensional geometric shapes that can be drawn on a plane. He can illustrate this definition with examples, such as a circle drawn on a sheet of paper. In addition, it should be emphasized that all plane figures are infinite, that is, they can be increased or decreased indefinitely without losing their characteristics.
   • Classification of Plane Figures (3 - 5 minutes): The teacher should then address the classification of plane figures, explaining that they can be classified into two main groups: polygons and circles. He can detail each of these categories, showing examples and discussing their characteristics. For example, polygons are closed plane figures formed by line segments, while circles are closed plane figures whose points are all the same distance from a point called the center.
   • Properties of Plane Figures (3 - 5 minutes): The teacher should then explain the properties of plane figures. He can start with the properties of polygons, such as the number of sides, the sum of the interior angles, the existence of diagonals, among others. Then, he should address the properties of circles, such as the radius, the diameter, the circumference, the arc, the circular sector, the chord, etc. The teacher should always illustrate the properties with practical examples and everyday situations, to facilitate the students' understanding.
   • Relationship between Plane Figures and Everyday Life (1 - 2 minutes): Finally, the teacher should reinforce the importance of studying plane figures, showing how they are present in our daily lives. He can cite examples of objects and constructions that have plane shapes, such as buildings, bridges, packaging, among others.

2. Resolution of Examples (5 - 10 minutes):

   • The teacher should then propose the resolution of some practical examples that involve the recognition and use of the properties of plane figures. For example, you can ask students to calculate the area of a triangle, the circumference of a circle, or the diagonal of a square. During the resolution, the teacher should guide the students, explaining step by step how to reach the correct answer.
   • In addition, the teacher should encourage students to look for plane figures in their environment, write down their observations and share them with the class. For example, a student might notice that the schoolyard is shaped like a rectangle, or that the lid of their pencil case is a square. This activity helps to fix the content in a playful and contextualized way.

3. Discussion and Clarification of Doubts (5 - 10 minutes):

   • Finally, the teacher should open a space for discussion about the content and for clarifying doubts. He can start by asking students if they understood the properties of plane figures and if they can identify these figures in their daily lives. Then, he should answer students' questions, clarifying the points that have not yet been understood. The teacher should encourage students to participate in the discussion, ask questions and express their difficulties, in order to promote a collaborative and supportive learning environment.

Review (10 - 15 minutes)

1. Connection with real life (3 - 5 minutes): The teacher should propose that the students reflect on how what they learned in class applies to the real world. They can be encouraged to discuss how plane figures are used in various contexts, such as in architecture, engineering, art, music, maps, among others. The teacher can ask students to share situations in which they recognized the presence of plane figures in their daily lives, or to imagine situations in which knowledge about plane figures could be useful. For example, they can think about how the properties of plane figures can be used to calculate the area of a garden, or to draw a symmetrical figure.

2. Learning verification (3 - 5 minutes): The teacher should propose a learning verification activity, in which the students will have to apply the concepts learned to solve a problem. For example, the teacher might present a challenge involving the calculation of areas or perimeters of plane figures, or requiring the recognition of a plane figure in an everyday object. Students should be encouraged to solve the problem in groups, in order to promote collaboration and exchange of ideas. After solving the problem, the teacher should propose a class discussion, in which the groups can present their solutions and explain how they arrived at them.

3. Final reflection (3 - 5 minutes): To end the class, the teacher should propose that the students reflect for a minute on the following questions:

   1. What was the most important concept you learned today?
   2. What questions have not yet been answered?
   3. What would you like to learn about plane figures in the future?

   Students should be encouraged to write down their answers, which can be used as a basis for preparing future classes. The teacher may also collect the answers and analyze them later, in order to evaluate the effectiveness of the class and identify possible gaps in the students' learning.

4. Teacher feedback (1 - 2 minutes): Finally, the teacher should give general feedback on the class, highlighting the positive points and areas that need improvement. He should also reinforce the importance of studying plane figures and encourage students to continue practicing the concepts learned. The teacher can, for example, suggest additional exercises to be solved at home, or propose an observation and recording activity of plane figures in the environment, which can be discussed in the next class.

This feedback is essential to consolidate learning, stimulate students' reflection on the content and promote the continuity of study outside the classroom.

Conclusion (5 - 10 minutes)

1. Summary of the main points (2 - 3 minutes): The teacher should begin the Conclusion by recapping the main points of the class. He can recall the definition of plane figures, the classification and properties of polygons and circles, and the importance of identifying and understanding these figures in our daily lives. This recap can be done through a brief review or a question and answer game with the class.

2. Connection between theory, practice and applications (1 - 2 minutes): The teacher should then highlight how the class connected theory, practice and applications. He can mention that, through the theoretical explanation and the resolution of practical examples, students were able to understand the properties of plane figures and how to apply them to solve problems. In addition, the teacher should emphasize that the study of plane figures is essential not only for the discipline of mathematics, but also for several other areas of knowledge and for everyday life.

3. Suggestion of extra materials (1 - 2 minutes): The teacher should suggest some extra materials for students who wish to deepen their knowledge on the subject. These materials may include books, websites, videos, games and mathematics applications that approach the study of plane figures in a playful and interactive way. The teacher can, for example, suggest that students explore the Khan Academy website, which offers a variety of educational resources on plane geometry and other mathematical topics.

4. Relevance of the topic for everyday life (1 - 2 minutes): Finally, the teacher should reinforce the importance of the topic for everyday life. He can remind students that plane figures are present in practically everything that surrounds us, from simple objects such as a pencil box to complex structures such as a skyscraper. In addition, the teacher should emphasize that knowledge about plane figures is essential for understanding various mathematical concepts and for the development of important skills, such as logical thinking and spatial perception.

5. Closing (1 minute): The teacher should close the class by thanking the students for their participation, encouraging them to continue studying the topic and wishing everyone a good day.