Lesson 3

Longitudes de lado específicas

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

Narrative

This warm-up prompts students to compare four images of shapes. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about attributes of the shapes in comparison to one another. During the synthesis, ask students to explain the meaning of any terminology they used, and if it does not come up, remind them of the term “square corners.”

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?

ATrapezoid.
BFour-sided shape.

CTwo shapes. Six-sided and four-sided.
DShape. Curved top and straight line at the bottom.

Student Response

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Activity Synthesis

  • “¿Qué hace que la figura A sea distinta a las demás?” // “What makes Shape A different from the others?” (It doesn’t have square corners.)
  • “¿Cómo pueden saber que no tiene esquinas cuadradas?” // “How can you tell it does not have square corners?” (A square wouldn’t fit in any of the corners in Shape A.)

Activity 1: Mide dos veces, dibuja una vez (15 minutes)

Narrative

The purpose of this activity is for students to identify and draw shapes that have specific side lengths. Students practice measuring in inches and centimeters. Students recognize that triangles, quadrilaterals, pentagons, and hexagons may look different when only some sides are the same length. 

Required Materials

Materials to Gather

Launch

  • Groups of 2
  • Give each student a ruler.

Activity

  • “Vamos a pensar más sobre figuras midiendo sus lados. Usen sus reglas para identificar y dibujar las figuras” // “We are going to think more about shapes by measuring their sides. Use your ruler to identify and draw the shapes.”
  • 7 minutes: independent work time
  • “Comparen las figuras que dibujaron con las figuras de su compañero” // “Compare the shapes you drew with your partner’s shapes.”
  • 5 minutes: partner discussion
  • Monitor for a variety of examples of Priya’s shape to share in the synthesis.

Student Facing

  1. Diego dibujó una figura que tiene menos de 5 lados. Dos de los lados miden 3 centímetros cada uno. Marca las figuras que pueden ser la figura de Diego.

    Hexagon.
    Triangle.
    Rectangle.
    Square.
  2. Tyler dibujó una figura que tiene 4 lados. Cada lado mide 2 pulgadas.

    1. Marca las figuras que pueden ser la figura de Tyler.

      Hexagon.
      Square.
      Square.
      Rhombus.
    2. Dibuja otra figura que pueda ser la figura de Tyler.

  3. Priya dibujó una figura que tiene más lados que la figura de Tyler. Solo un lado de la figura mide 2 pulgadas. Dibuja dos figuras que puedan ser la figura de Priya.

Student Response

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Advancing Student Thinking

If students' measurements are not the length of the given sides when measuring or drawing shapes, consider asking:

  • “¿Puedes mostrarme cómo mediste los lados de esta figura?” //  “Can you show me how you measured the sides of this shape?”
  • “¿Cómo puedes usar la regla para asegurarte de que el lado mide 2 pulgadas?” //   “How can you use the ruler to make sure the side is 2 inches long?”

Activity Synthesis

  • Select 2–3 previously identified students to share, or draw some examples, such as:
    Student-drawn shapes.
  • Consider asking, “¿En qué se parecen estas figuras? ¿En qué son diferentes?” // “What is the same about these shapes? What is different?” 
  • “¿Por qué pudimos dibujar tantas figuras distintas aunque se tuviera que usar una longitud específica?” // “Why were we able to draw so many different shapes even though you had to use a certain length?” (Only one side had to be 2 inches. We could draw shapes with different numbers of sides.)

Activity 2: Construyamos una figura (20 minutes)

Narrative

The purpose of this activity is for students to recognize and draw shapes that have a specific number of sides and corners, and specific side lengths. Students deepen their understanding that shapes in the same category can share many attributes and look different. Students also notice that some attributes can’t go together to form a shape (for example, a shape can’t have 3 sides and 4 corners, or 3 sides and all square corners).

Students may persevere in problem solving if they look for or choose particular attributes that do not go together (MP1). In some cases, such as a shape with 3 sides and 4 corners, they may be able to see right away that no such shape exists. But in other cases, such as a shape with 3 sides and 2 square corners or 6 sides and all square corners, they will need to experiment and reason in order to predict that no such shape exists. 

MLR8 Discussion Supports. Invite students to begin partner interactions by repeating the question, “¿Cuáles características corresponden a la figura que dibujé?” // “Which attributes match the shape I drew?” This gives both students an opportunity to produce language.
Advances: Conversing
Action and Expression: Internalize Executive Functions. Invite students to verbalize their strategy for the shape they will build before they begin. Students can share with their partner.
Supports accessibility for: Organization, Conceptual Processing, Language

Required Materials

Materials to Gather

Launch

  • Groups of 2
  • Give students access to rulers.
  • Display the attribute table.
  • “Hemos aprendido sobre características de figuras. Esta tabla muestra algunas de las características de figuras sobre las que hemos pensado, como número de lados, número o tipo de esquinas, y longitudes de lado específicas” // “We have been learning about attributes of shapes. This table shows some of the attributes of shapes we have been thinking about, such as number of sides, numbers or types of corners, and specific lengths of sides.”
  • Draw or display a rectangle with two sides that are 3 inches long.
  • “¿Cuáles características de esta tabla piensan que se escogieron para dibujar esta figura?” // “What attributes do you think were picked from this table to draw this shape?” (4 sides, 4 corners, all corners are square corners, 2 sides are the same length. It’s either 2 sides are 2 inches or 2 sides are 3 inches long.)
  • Circle the attributes that students identify on the attribute table.

Activity

  • “Ahora van a tener la oportunidad de escoger sus propias características, dibujar sus figuras y adivinar cuáles características escogió su compañero” // “Now you will get a chance to pick your own attributes, draw your own shapes, and guess which attributes your partner picked.”
  • “Si les queda tiempo, respondan el último problema con su compañero” // “If you have time, work with your partner to answer the last problem.”
  • 5 minutes: independent work time
  • 5 minutes: partner work time
  • Monitor for:
    • a variety of triangles, quadrilaterals, pentagons, and hexagons
    • students who attempt to combine attributes that do not result in a shape

Student Facing

  1. Escoge tus propias características. Marca una característica en cada fila.

    lados 3 4 5 6
    esquinas 3 4 5 6
    longitud de lados 1 lado mide 2 pulgadas. 2 lados miden 2 pulgadas. 2 lados miden 3 pulgadas. 4 lados miden 2 pulgadas.

    esquinas
    cuadradas

    0 1 2

    todas las esquinas cuadradas

    Dibuja y nombra una figura que tenga las características que escogiste. Si no puedes dibujar la figura, explica por qué.

    Figura:

    Nombre: ______________________________

  2. Escoge tus propias características. Marca una característica en cada fila.

    lados 3 4 5 6
    esquinas 3 4 5 6
    longitud de lados 1 lado mide 2 pulgadas. 2 lados miden 2 pulgadas. 2 lados miden 3 pulgadas. 4 lados miden 2 pulgadas.

    esquinas cuadradas

    0 1 2

    todas las esquinas cuadradas

    Dibuja y nombra una figura que tenga las características que escogiste. Si no puedes dibujar la figura, explica por qué.

    Figura:

    Nombre: ______________________________

  3. Escoge tus propias características. Marca una característica en cada fila.

    lados 3 4 5 6
    esquinas 3 4 5 6
    longitud de lados 1 lado mide 2 pulgadas. 2 lados miden 2 pulgadas. 2 lados miden 3 pulgadas. 4 lados miden 2 pulgadas.

    esquinas
    cuadradas

    0 1 2 todas las esquinas cuadradas

    Dibuja y nombra una figura que tenga las características que escogiste. Si no puedes dibujar la figura, explica por qué.

    Figura:

    Nombre: ______________________________

  4. Cubre tu tabla de características e intercambia hojas con tu compañero. Adivina cuáles características usó tu compañero para dibujar su figura.
  5. Si te queda tiempo: ¿Hay algunas características que sea imposible escogerlas juntas para hacer una figura? Explica o muestra.

Student Response

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Activity Synthesis

  • Invite previously selected students to share the shapes they drew.
  • For each, ask, “¿Qué características piensan que ellos usaron para hacer esta figura?” // “What attributes do you think they used to make this shape?”
  • 30 seconds: quiet think time
  • Share responses.
  • Display student work that shows attributes that do not make a shape, or share attributes and display an image like the following:
    • 4 sides, 3 corners, 2 sides are 2 inches, 1 square corner
    •  
      Student shape.
  • “¿Por qué piensan que _____ no pudo terminar esta figura?” // “Why do you think _____ couldn’t finish this shape?”

Lesson Synthesis

Lesson Synthesis

“Hoy usamos medidas de longitud para identificar y dibujar figuras” // “Today, we used length measurements to identify and draw shapes.”

Display:

“4 lados
4 esquinas cuadradas
Cada lado mide 3 pulgadas de largo” // 
4 sides
4 square corners
Each side is 3 inches long.

“Clare dibujó una figura que tiene estas tres características. ¿Cuál figura dibujó Clare? Descríbanle a su compañero cómo se ve la figura” // “Clare drew a shape that has these attributes. Which shape did Clare draw? Describe to your partner what the shape would look like.” (Clare drew a quadrilateral. It should look like a square.)

Display:

“6 lados
5 esquinas” // 
6 sides
5 corners

“Diego quería dibujar una figura con estas características. ¿Es posible? Expliquen” // “Diego wanted to draw a shape with these attributes. Is it possible? Explain.” (No. The shape would not be able to close without having the same number of sides and corners. The shape would need to have the same number of sides and corners.)

Cool-down: Dibuja la figura (5 minutes)

Cool-Down

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