Lesson 5

Algunos triángulos, todos los triángulos

Warm-up: Cuál es diferente: Figuras (10 minutes)

Narrative

This warm-up prompts students to compare four two-dimensional shapes. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use informal and formal language to talk about characteristics of the items in comparison to one another. During the synthesis, ask students to explain the meaning of any terminology they use, such as curved and open.

Launch

• Groups of 2
• Display the image.
• “Escojan una que sea diferente. Prepárense para compartir por qué es diferente” // “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

Activity

• “Discutan con su compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 2–3 minutes: partner discussion
• Share and record responses.

Student Facing

¿Cuál es diferente?

Activity Synthesis

• “Encontremos al menos una razón por la que cada una es diferente” // “Let’s find at least one reason why each one doesn’t belong.”

Activity 1: Triángulos y “no triángulos” (10 minutes)

Narrative

The purpose of this activity is for students to analyze examples and non-examples of triangles. As students compare examples and non-examples, they identify and articulate the defining attributes of triangles (MP6).

MLR8 Discussion Supports. Before students share, remind them to use words such as sides, corners, straight, and pointy.
Representation: Internalize Comprehension. Synthesis: Provide more examples and non-examples to reinforce the defining attributes of triangles.
Supports accessibility for: Conceptual Understanding, Visual-Spatial Processing

Required Materials

Materials to Gather

Required Preparation

• Each group of 2 needs a set of Flat Shape Cards from a previous lesson.

Launch

• Groups of 2
• Display the first question.
• “Estos son cuatro triángulos. ¿Qué tienen en común todos estos triángulos?” // “Here are four triangles. What do all of these triangles have in common?” (They all have three sides and three corners. They are all pointy. They are all closed.)
• 30 seconds: quiet think time
• “Compartan con su pareja lo que pensaron” // “Share your thinking with your partner.”
• 2 minutes: partner discussion
• Share responses.
• If a student shares that all the triangles are white, ask, “Si coloreo una de estas figuras de rojo, ¿sigue siendo un triángulo?” // “If I colored one of these shapes in red, would it still be a triangle?”

Activity

• “Piensen con su pareja qué hace que estos ‘no triángulos’ sean diferentes de los triángulos del primer problema” // “Work with your partner to think of what makes these ‘not triangles’ different from the triangles in the first problem.”
• 3 minutes: partner discussion

Student Facing

1. Estos son triángulos.

¿En qué se parecen todos estos triángulos?

2. Estos no son triángulos.

¿Qué hace que estas figuras sean diferentes a los triángulos?

Activity Synthesis

• “¿Qué hace que los triángulos sean diferentes de los ‘no triángulos’?” // “What makes the triangles different than the 'not triangles'?”
• Give each group a set of shape cards from previous lessons.
• “Clasifiquen con su pareja sus tarjetas de figura en las categorías de ‘triángulos’ y ‘no triángulos’” // “Work with your partner to sort your shape cards into the categories of ‘triangles’ and ‘not triangles.’”
• Share responses.

Activity 2: Dibujemos triángulos (10 minutes)

Narrative

The purpose of this activity is for students to draw triangles. Students use dot paper to draw triangles and then draw shapes that are not triangles. Students may use the shape cards to visualize and draw shapes.

Required Materials

Materials to Gather

Materials to Copy

• Centimeter Dot Paper - Standard

Required Preparation

• Each group needs a set of Flat Shape Cards from the previous activity.

Launch

• Groups of 2
• Give each group a set of flat shape cards and two pieces of dot paper.
• “Escojan tres puntos. Unan los puntos” // “Choose three dots. Connect the dots.”
• 30 seconds: independent work time
• “Comparen su dibujo con el de su pareja. ¿Qué observan?” // “Compare your drawing with your partner. What do you notice?” (We both drew triangles. The triangles are different sizes. They both have three sides.)
• 1 minute: partner share
• Share responses.

Activity

• “En el papel de puntos de su libro, dibujen tres triángulos y tres figuras que no sean triángulos. Pueden usar las tarjetas de figura para ayudarse” // “Use the dot paper in your book to draw three triangles and three shapes that are not triangles. You may use the shape cards to help you.”
• 6 minutes: independent work time
• Monitor for some triangles and 'not triangles' to share during the lesson synthesis.

Student Facing

1. Dibuja 3 triángulos diferentes.

2. Dibuja 3 figuras diferentes que no sean triángulos.

Activity Synthesis

• “¿Quién cree que dibujó un triángulo que nadie más dibujó?” // “Who thinks they drew a triangle that no one else drew?”
• Invite students to share their shapes and explain how they know they are triangles.

Activity 3: Centros: Momento de escoger (20 minutes)

Narrative

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting or working with shapes. Students choose from any stage of previously introduced centers.

• Geoblocks
• How Are They the Same
• Compare
• How Close

Required Materials

Materials to Gather

Required Preparation

Gather materials from previous centers:

• Geoblocks, Stage 3
• How Are They the Same?, Stage 1
• Compare, Stage 1
• How Close, Stages 1-3

Launch

• Groups of 2
• “Ahora van a escoger centros de los que ya conocemos” // “Now you are going to choose from centers we have already learned.”
• Display the center choices in the student book.
• “Piensen qué les gustaría hacer primero” // “Think about what you would like to do first.”
• 30 seconds: quiet think time

Activity

• Invite students to work at the center of their choice.
• 8 minutes: center work time
• “Escojan qué les gustaría hacer ahora” // “Choose what you would like to do next.”
• 8 minutes: center work time

Student Facing

Escoge un centro.

Bloques sólidos geométricos

¿En qué se parecen?

Compara

¿Qué tan cerca?

Activity Synthesis

• “¿Cómo decidieron qué centros escoger hoy?” // “How did you decide which centers to choose today?”

Lesson Synthesis

Lesson Synthesis

“Hoy observamos figuras que son triángulos y figuras que no son triángulos. Después, dibujamos nuestras propias figuras” // “Today we looked at shapes that are triangles and shapes that are not triangles. Then we drew our own shapes.”

Display shapes drawn in a previous activity. “¿Cómo podemos saber si estas figuras son triángulos o no?” // “How can we tell if these shapes are triangles or not?” (If they are triangles they will have three sides, three corners, the sides will be straight and the shapes will be closed.)