Objectives (5 - 7 minutes)

1. Understanding the concept of angles: Students should be able to understand what an angle is and how it is formed by two lines meeting at a point.

2. Differentiating between right and non-right angles: Students should be able to distinguish between right angles, which measure exactly 90 degrees, and non-right angles, which can measure more or less than 90 degrees.

3. Identifying right and non-right angles in everyday objects: Students should be able to recognize right and non-right angles in objects and situations from daily life, such as in a rectangular box or in the meeting of walls in the classroom.

Secondary Objectives:

• Stimulate curiosity and interest in mathematics: Through practical examples and the use of concrete materials, students should be encouraged to engage and be interested in the subject.

• Promote teamwork and verbal communication: Group activities and class discussions should be encouraged so that students can share their discoveries and understandings.

Introduction (10 - 12 minutes)

1. Recalling concepts: The teacher starts the lesson by reminding students about basic geometry concepts, such as straight lines, curves, and two-dimensional shapes. This is important for students to have a solid foundation to understand the concept of angles.

2. Problem situation: The teacher presents two problem situations to spark students' interest:

   • "Have you noticed that windows and doors usually have a rectangular shape? Why do you think this happens?"

   • "And when you draw a house, why do you draw the roof in a triangular shape?"

   These questions help introduce the concept of right angles (90°) and non-right angles.

3. Contextualization: The teacher explains that understanding angles is important in our daily lives because it helps us understand how things are built and how they fit together. For example, in a house, right angles are used to build the walls, and furniture is designed to fit into certain angles.

4. Capturing students' attention: The teacher shares two curiosities about angles:

   • "Did you know that the word 'angle' comes from Latin and means 'corner'? This is because angles are formed at the corners where two lines meet."

   • "And did you know that mathematicians use a special unit to measure angles? It's the degree (°). A full circle has 360° and a right angle has 90°, for example."

5. Introduction to the topic: Finally, the teacher introduces the topic of the lesson, explaining that they will learn more about angles, especially about right and non-right angles, and how they are present in our daily lives. The teacher also emphasizes that they will explore the theme in a fun way, through games and interactive activities.

Development (20 - 25 minutes)

1. Angle Theory (10 - 12 minutes)

   • The teacher starts the topic by explaining that an angle is formed when two lines meet at a point.
   • A simple angle is drawn on the board, showing the two lines and the meeting point, explaining that this point is called the vertex of the angle.
   • It is important to reinforce that angles are measured in degrees, a unit of measurement that students should already be familiar with.
   • The teacher demonstrates how to measure an angle with a protractor, placing the central point of the protractor at the angle's vertex and aligning the base line with one of the angle's lines. Then, the angle value is read on the protractor's scale.
   • After this introduction, the teacher moves on to explain right and non-right angles.

2. Right Angles (5 - 7 minutes)

   • The teacher draws a right angle on the board, showing that it has an exact measurement of 90 degrees, which is a quarter of a circle.
   • It is important to reinforce that the right angle is a very common figure in our daily lives, being observed in objects such as windows, doors, frames, tables, books, among others.
   • The teacher can ask questions to the class, encouraging them to identify right angles in objects in the classroom environment.

3. Non-Right Angles (5 - 7 minutes)

   • The teacher draws a non-right angle on the board, demonstrating that its measurement is greater or less than 90 degrees.
   • It is explained that non-right angles are also common in our daily lives and can be observed, for example, in clock hands, house roofs, trees, among others.
   • The teacher can propose a game with the class, where they must identify right and non-right angles in various images projected on the board.

4. Reinforcement and Practice (5 - 7 minutes)

   • The teacher should reinforce the explained theory, reviewing the concepts of angles, right angles, and non-right angles.
   • To solidify learning, the teacher proposes a practical activity. Students are divided into groups and receive a sheet with several angle drawings. They must identify if the angle is right or non-right and mark the angle's measurement, if possible.
   • The teacher circulates around the room, assisting the groups, clarifying doubts, and checking each group's progress.

Throughout the development, it is important for the teacher to use clear and simple language, avoiding very technical or complex terms. The teacher should pay attention to students' doubts and questions, always seeking to clarify them in a didactic and effective way. The teacher can also take advantage of the lesson to correct possible misconceptions that students may have about the topic, reinforcing the correct concepts.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes)

   • The teacher gathers all students in a large circle for a group discussion. Each group is invited to share their conclusions and solutions found during the practical activity.
   • Students are encouraged to explain how they arrived at their answers, what criteria they used to distinguish right angles from non-right angles, and what strategies they used to measure the angles, if possible.

2. Connection with Theory (2 - 3 minutes)

   • The teacher then makes the connection between the solutions or conclusions presented by the students and the theory presented at the beginning of the lesson.
   • It is important for the teacher to highlight again the concepts of right and non-right angles, and how they can be observed in our daily lives.
   • The teacher can use the solutions presented by the students to exemplify and reinforce the theoretical concepts, clarifying possible doubts that may still exist.

3. Final Reflection (3 - 4 minutes)

   • To conclude the lesson, the teacher proposes that students reflect on what they have learned. Two questions are presented to guide this reflection:

     1. "Why is it important to know and understand about right and non-right angles?"
     2. "How can you apply what you learned today in everyday situations?"

   • Students are encouraged to share their reflections with the class. The teacher reinforces that understanding the importance and application of mathematical concepts is essential for their learning and development.

Throughout the return, it is essential for the teacher to create a safe and welcoming environment where students feel comfortable sharing their ideas, doubts, and reflections. The teacher should value each student's contributions, encouraging the active participation of all. Additionally, it is important for the teacher to be attentive to possible difficulties or doubts that may still exist, so they can be addressed in future lessons.

Conclusion (5 - 7 minutes)

1. Lesson Summary (2 - 3 minutes)

   • The teacher starts the conclusion by summarizing the main points covered during the lesson. They reinforce the definition of an angle as the union of two lines at a point, the concept of a right angle (90°) and a non-right angle (more or less than 90°), and the importance of identifying and understanding these concepts in our daily lives. The teacher can use the board to draw and review the different types of angles.
   • The teacher also reinforces the practical applications of what was learned, such as identifying angles in objects and situations from daily life.

2. Connection between Theory and Practice (1 - 2 minutes)

   • The teacher explains how the lesson connected angle theory with practice. They emphasize that the theory presented at the beginning of the lesson was applied during the practical activity, and that students had the opportunity to observe and identify right and non-right angles in different contexts.
   • The teacher also highlights that the practical activity allowed students to put into practice the theoretical concepts learned, which helps to solidify knowledge more effectively.

3. Extra Materials (1 minute)

   • The teacher suggests some extra materials for students who wish to deepen their knowledge on the subject. This may include math books with sections on geometry, educational online games about angles, and explanatory videos available on the internet.
   • The teacher can also suggest activities to be done at home, such as identifying right and non-right angles in objects from the familiar environment, or measuring angles of objects using a protractor.

4. Importance of the Subject (1 minute)

   • Finally, the teacher concludes the lesson by reinforcing the importance of understanding right and non-right angles. They explain that this is an essential mathematical skill that helps to understand the shapes and structures around us.
   • The teacher also emphasizes that mathematics is a discipline very present in our daily lives, and that understanding mathematical concepts can help us make more informed decisions and solve problems more effectively.

Throughout the conclusion, it is important for the teacher to maintain clear and accessible language, and to be attentive to students' engagement and understanding. The teacher should encourage students to ask questions and share their observations and reflections. Additionally, the teacher can use this conclusion as an opportunity to assess students' progress and identify possible points to reinforce in future lessons.