Objectives (5 - 7 minutes)

1. Understand what angles are: Students should be able to identify and understand the concept of angles, which are formed by two lines intersecting at a point. They should understand that angles are measured in degrees and that the angle's opening determines its classification.

2. Identify the opening of angles: Students should be able to identify the opening of an angle based on their visualization and understanding of the numerical value of degrees. They should be able to distinguish between acute, right, and obtuse angles based on the opening.

3. Classify angles based on their opening: Students should be able to classify angles as acute, right, and obtuse based on their openings. They should understand that acute angles have openings less than 90 degrees, right angles have openings of 90 degrees, and obtuse angles have openings greater than 90 degrees.

Students will be encouraged to learn the lesson objectives by watching explanatory videos and doing practical activities at home. During the lesson, the teacher will review the concepts with the class and propose cooperative activities to reinforce learning.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher will start the lesson by reminding students about the concept of straight lines and what they have learned about them in previous classes. He may draw some straight lines on the board and ask students to identify them. This will help establish the foundation for understanding angles.

2. Problem Situation 1: The teacher can propose the following situation: 'Imagine you are on a soccer field and want to know where the ball is going. How can you use the lines on the field to help you figure out the ball's path?' This will lead students to think about how lines can form angles and how these angles can help determine direction.

3. Problem Situation 2: Another situation the teacher can present is: 'You are in a classroom and want to find out if the wall in front of you forms a right angle with the floor. How can you do that?' This situation helps introduce the concept of a right angle and how it can be identified.

4. Importance of the topic: The teacher will explain that understanding angles is important in many everyday life situations, such as playing soccer, building things, drawing, and even when using a clock. He may give examples of how angles are used in these situations to make the topic more relevant to students.

5. Introduction to the topic: The teacher will introduce the lesson topic by saying, 'Today, we will learn about angles and how they are used to describe the opening between two lines. Let's find out how we can classify angles based on their opening. This will help us better understand the world around us.' The teacher may display images of simple angles, such as a right angle, an obtuse angle, and an acute angle, to familiarize students with them.

During the introduction, the teacher should ensure that all students are involved and understand the concepts presented. He can encourage student participation by asking questions and requesting that they share their observations and ideas. This section of the lesson should be interactive and fun to engage students and spark their interest in the topic.

Development (20 - 25 minutes)

1. Activity 1: Measuring angles in the classroom

   • The teacher will prepare cards with different angles drawn on them (acute, right, and obtuse). The angles can be drawn in advance or students can be asked to help draw them.
   • Students will be divided into groups of 4 or 5, and each group will receive a set of cards.
   • The teacher will explain that they must work together to identify the type of angle on each card, observing the 'opening' of the angle.
   • Each group will have a protractor to measure the angle if necessary. The teacher should provide clear instructions on how to use a protractor correctly.
   • After each group classifies all the cards, they will discuss their findings with the whole class.

2. Activity 2: Creating angles with toys and objects

   • The teacher will ask students to bring some toys or objects from home (such as pencils, erasers, books, etc).
   • Students will be divided into groups, and each group will receive a task. For example, one group may be instructed to create acute angles, another right angles, and another obtuse angles, all using the objects brought.
   • After completing the task, students should present to the class the angles they created and explain why they classified them that way.

3. Activity 3: Angle treasure hunt

   • The teacher will hide several cards around the classroom, each with an angle drawn on it.
   • Students will be divided into groups and given a list of angles to find (for example, two obtuse angles, three right angles, etc).
   • They will have to search for the cards, identify the angle, and correctly classify it on their list. The first group to find all angles correctly will be the winner.

The teacher should choose one or two activities, depending on the available time and the dynamics of the class. The activities are designed to be interactive, allowing students to work together and apply what they have learned about angles and their classification. Additionally, they encourage communication and problem-solving in groups, important skills for student development. During the activities, the teacher should circulate around the room, offering support and facilitating discussion if necessary.

Return (10 - 15 minutes)

1. Group discussion (5 - 7 minutes):

   • The teacher will gather all students in a large circle for a group discussion. Each group will have the opportunity to present their findings and solutions from the activities. The teacher may ask the representatives of each group to show the angles they classified and explain their classification.
   • During the presentations, the teacher will ask questions to stimulate critical thinking and deepen students' understanding. For example, 'Why do you think this angle is acute and not obtuse?' or 'How do you know this angle is right without measuring?'
   • The teacher will also encourage the participation of all students by asking if they agree or disagree with the classifications and why. This will help develop the skill of argumentation and respect for others' opinions.

2. Connection to theory (3 - 5 minutes):

   • After the presentations, the teacher will recap the theoretical concepts discussed at the beginning of the lesson, reinforcing the idea that the angle's opening determines its classification.
   • The teacher can use examples from the activities to make the connection to the theory. For example, 'Do you remember the angle that group X created with the pencils? Why did you classify that angle as obtuse?' or 'When we measured the angle on the card, what can we say about its classification?'

3. Individual reflection (2 - 3 minutes):

   • To conclude the lesson, the teacher will propose that students reflect for a minute on what they have learned. He will ask two simple questions to guide the reflection:
     1. 'What was the most interesting thing you learned about angles today?'
     2. 'How can you use what you learned about angles in real life?'
   • After a minute, the teacher will invite some students to share their answers with the class. This will not only allow students to consolidate their learning but also give them the opportunity to express their creativity and apply what they have learned in practical ways.

During the return, the teacher should ensure that all students actively participate in the discussion and reflection. He should praise the students' effort and collaboration, reinforcing that everyone has the ability to learn and that mistakes are part of the learning process. This will help maintain a positive and encouraging learning environment where students feel comfortable expressing their ideas and learning from others.

Conclusion (5 - 7 minutes)

1. Lesson Summary (2 - 3 minutes):

   • The teacher will start the conclusion by recalling the main points covered during the lesson. He will recap the concept of angles, their definition, and how they are formed.
   • Next, he will emphasize the importance of the angles' opening and how this characteristic determines their classification as acute, right, and obtuse. He can do this through quick questions for students to verify if they remember the concepts.

2. Connection between theory and practice (1 - 2 minutes):

   • The teacher will then explain how the activities carried out during the lesson helped connect the theory of angles with practice. He may mention, for example, how creating angles with everyday objects helped students better understand the concept of angle opening.
   • The teacher may also mention how the angle treasure hunt encouraged students to apply what they learned in a practical way while working in teams to solve problems.

3. Extra materials (1 - 2 minutes):

   • The teacher will suggest some extra materials for students who want to deepen their knowledge on the subject. This may include math books with explanations and exercises on angles, educational websites with interactive games on the topic, and explanatory videos available on the internet.
   • The teacher should emphasize that these materials are optional but can be very useful for consolidating learning and exploring the subject in different ways.

4. Relevance of the subject (1 minute):

   • To conclude, the teacher will reinforce the importance of the subject for students' daily lives. He may mention, for example, how knowledge about angles can help them draw better, understand the rules of board games that involve movement on a plane, and even use an analog clock.
   • The teacher may also emphasize that the ability to identify and classify angles is an important skill in various fields, such as architecture, engineering, graphic design, and computer science.

During the conclusion, the teacher should ensure that students feel confident in their understanding of angles and know where to find more information if they wish. He should encourage students to continue exploring and learning about the subject, thus promoting autonomous learning and intellectual curiosity.