# Lesson 7

Juntemos figuras planas

## Warm-up: Observa y pregúntate: Perros (10 minutes)

### Narrative

The purpose of this warm-up is to elicit student knowledge about composing and decomposing composite shapes, which will be useful when students build their own composite shapes later in this lesson. While students may notice and wonder many things about this image, the idea that shapes, such as hexagons, can be composed and decomposed into other shapessuch as multiple triangles, rhombuses, trapezoids, or a combination of triangles, rhombuses, or trapezoidsis the important discussion point. Students may refer to the pattern blocks by their colors when describing them or sharing different combinations that may form the same shape. Use this as an opportunity to ask the students if they know the names of the shapes and review shape vocabulary.

### Launch

• Groups of 2
• Display the image.
• “¿Qué observan? ¿Qué se preguntan?” // “What do you notice? What do you wonder?”
• 1 minute: quiet think time

### Activity

• “Discutan con un compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

### Student Facing

¿Qué observas?
¿Qué te preguntas?

### Activity Synthesis

• “Algunos de ustedes se dieron cuenta de que la imagen de la parte de abajo se parece a la de arriba, pero se usaron figuras diferentes para formar los hexágonos” // “Some of you noticed that the image at the bottom looks like the one at the top, but they used different shapes to make up the hexagons.”
• “¿De qué otras maneras podrían armar un hexágono con las fichas geométricas?” // “What other ways could you make a hexagon with the pattern blocks?” (2 trapezoids, 1 trapezoid and 3 triangles, 2 rhombuses and 2 triangles)
• “¿De qué otras maneras podrían armar un rombo?, ¿un trapecio?” // "What other ways could you make a rhombus? a trapezoid?”

## Activity 1: Construyamos con fichas geométricas (15 minutes)

### Narrative

The purpose of this activity is for students to compose two-dimensional shapes into larger shapes in different ways. As students work, consider asking them to identify the shapes they are using and their attributes. During this activity, the teacher may consider taking photos of the way students composed the large triangle (third problem) and the large rectangle (fourth problem) to share during the synthesis so that students do not need to move their pattern blocks to share with the class.

MLR8 Discussion Supports. Synthesis: When asking questions, invite students to take turns sharing their responses. Ask students to restate what they heard using precise mathematical language and their own words. Display the sentence frame: “Te escuché decir . . .” // “I heard you say . . .” Original speakers can agree or clarify for their partner.

### Required Materials

Materials to Gather

Materials to Copy

• Flat Shapes Puzzles, Spanish

### Required Preparation

• Consider making the Flat Shapes Puzzles blackline master into a packet for each student.

### Launch

• Give students pattern blocks and the flat shape puzzles.

### Activity

• “Usen las fichas geométricas para llenar la figura de diferentes maneras. Cada vez, usen imágenes, números o palabras para mostrar cómo llenaron la figura” // “Use the pattern blocks to fill the outline in different ways. Each time, record how you filled in the shape with pictures, numbers, or words.”
• 8 minutes: independent work time
• Monitor for different ways that students filled in the large triangle and large rectangle puzzles.

### Activity Synthesis

• Display work from two students for the large triangle.
• “¿Cómo armaron el triángulo de maneras diferentes? ¿Por qué las dos maneras funcionan?” // “How was the triangle created differently? Why do both ways work?” (One way used all triangles, the other used some triangles and a trapezoid. They both work because a trapezoid is the same shape as three triangles put together.)
• Display student work for the large rectangle.
• “¿Alguien encontró una manera diferente de construir esta figura? ¿Por qué no pudimos encontrar otras maneras?” // “Did anyone find a different way to build this shape? Why didn’t we find any other ways?” (The rectangle has square corners and the square is the only pattern block that also has square corners.)

## Activity 2: Imágenes de figuras (10 minutes)

### Narrative

The purpose of this activity is for students to compose two-dimensional shapes into composite shapes and find other smaller shapes that can make the same composite shape. Students use pattern blocks to compose a new shape, then recreate the new shape using smaller shapes.

Action and Expression: Internalize Executive Functions. Check for understanding by inviting students to rephrase directions in their own words.
Supports accessibility for: Memory, Organization

### Required Materials

Materials to Gather

### Launch

• Give students pattern blocks.
• “¿Qué tipos de figuras pueden armar con estas fichas geométricas?” // “What kinds of shapes can you make from pattern blocks?” (triangles, rectangles, flowers)
• 30 seconds: quiet think time
• Share responses.

### Activity

• “Usen las fichas geométricas para construir algo nuevo. Pueden construir lo que quieran. Después de construir el objeto nuevo, trácenlo y cuenten el número de fichas que usaron. Después, construyan el mismo objeto usando fichas diferentes y escriban cuántas fichas usaron” // “Use the pattern blocks to build something new. You can build whatever you want. After you build your new object, trace it and count the number of pattern blocks you used. Then build the same object using different pattern blocks, and record how many blocks you used.”
• 6 minutes: independent work time
• Monitor for 2–3 students to share their two shapes.

### Student Facing

1. Construye algo usando las fichas geométricas.

Traza lo que hiciste y escribe cuántas fichas geométricas usaste.

2. Arma el mismo objeto que hiciste usando fichas geométricas diferentes.

Escribe cuántas fichas geométricas usaste.

Si te queda tiempo: construye el mismo objeto otra vez usando la mayor cantidad de fichas geométricas que puedas.
Escribe cuántas fichas geométricas usaste.

### Activity Synthesis

• Invite previously identified students to share.
• “¿Qué observaron sobre las figuras que ellos construyeron?” // “What do you notice about the shapes they built?” (They made a rocket. They used six triangles to make a hexagon in their first shape but used hexagons in the second shape.)
• Repeat as time allows.

## Activity 3: Conozcamos “Libros de imágenes: Encuentra figuras” (15 minutes)

### Narrative

The purpose of this activity is for students to learn stage 3 of the Picture Books center introduced in kindergarten. Students look through picture books and notice and describe shapes they see in the pictures. Students record the shapes they see with drawings or words.

### Required Materials

Materials to Gather

Materials to Copy

• Picture Books Stage 3 Recording Sheet, Spanish

### Required Preparation

• Each group of 2 needs at least one picture book that shows a variety of shapes throughout the book.

### Launch

• Groups of 2
• Give each group two recording sheets and access to picture books.
• “Vamos a buscar figuras en libros de imágenes. Hablen con su pareja sobre las figuras que ven. Describan las figuras y nómbrenlas si pueden. Después, usen dibujos o palabras para registrar las figuras que ven” // “We are going to look for shapes in picture books. Talk to your partner about the shapes you see. Describe the shapes and name them if you can. Then record the shapes you see with a drawing or words.”

### Activity

• 10 minutes: partner work time

### Activity Synthesis

• Display a page from a picture book with lots of recognizable shapes.
• “¿Qué figuras ven en esta página?” // “What shapes do you see on this page?” (The sun looks like a circle. The blanket is a rectangle. The ball is a sphere.)

## Lesson Synthesis

### Lesson Synthesis

Display a chart titled “Lo que hemos aprendido sobre las figuras” // “What We've Learned About Shapes.”

“Reflexionemos sobre lo que hicimos con figuras en esta sección. Primero, van a pensar individualmente. Después, van a compartir sus ideas con un compañero” // “Let’s reflect on the work we did in this section with shapes. First you will think on your own. Then you will share your ideas with a partner.”

Share and record responses.

## Student Section Summary

### Student Facing

Aprendimos sobre figuras sólidas.

Aprendimos sobre figuras planas.

Describimos y nombramos figuras.

Esta figura es un triángulo porque tiene 3 lados rectos y 3 esquinas.