Area of Composite Figures

My Notes Level 1 Support Level 2 Standard Level 3 Enrichment

Today's objectives

Content Objective: I can find the area of a composite figure by adding or subtracting the areas of basic shapes.

Language Objective: I can explain my steps using the words composite figure, decompose, add, and subtract.

📖 See Learn It for the explanation and worked examples, and the Vocab tab for the words. These are your notes to fill in and keep.

✏️ Fill in each blank as we go. Use the Word Bank to help you.

📚 Word Bank — fill each blank with the best word

👆 Tap any word to see what it means and a picture.

Level 3: try the blanks from memory first, then check the bank.

1A shape made of two or more basic shapes combined is a .
2To break a composite figure into basic shapes is to it.
3To find the total area of separate parts, I their areas.
4To find the area of a shape with a piece removed, I the missing part's area.
5A math rule written with symbols is a .

Write About the Math Guided ESOL writing

Use the support level you need. Every level answers the same math question.

1. Understand the Question

explain

For the U-shaped pool you subtracted a 6 ft by 4 ft cutout from a 14 ft by 10 ft rectangle. How do you decide when to ADD areas and when to SUBTRACT?

Your job: Answer the question. Use math evidence. Explain how the evidence proves your answer.Responde la pregunta. Usa evidencia matemática. Explica cómo la evidencia demuestra tu respuesta.

2. Plan Your Math Words

Check at least two words you will use.

Composite Figure — A shape made by putting two or more simple shapes together.Figura compuesta — Una figura formada al juntar dos o más figuras simples. Decompose — To break a shape into smaller, simpler shapes.Descomponer — Separar una figura en figuras más pequeñas y simples. Add — Add up the areas of the smaller shapes to get the total.Sumar — Sumar las áreas de las figuras pequeñas para obtener el total. Subtract — Take away the area of a missing piece from a bigger shape.Restar — Quitar el área de una parte que falta de una figura más grande. Formula — A math rule written with symbols.Fórmula — Una regla matemática escrita con símbolos.

Say it first: Say your idea to a partner or quietly to yourself before you write.Di tu idea a un compañero o en voz baja antes de escribir.

I broke the figure into ___.Dividí la figura en ___.

3. Build Your Explanation

Model the parts: This model shows the parts of an explanation. It does not answer your writing question.

Claim: We decompose the L-shape because we already know how to find a rectangle's area.

Evidence: Students explain that the L-shape is hard to measure directly, so breaking it into two rectangles lets them use A = l x w on each piece and add the results.

Reasoning: This evidence connects the definition of composite figure to the mathematical claim.

Start

Most language support

Complete the frames. Use the word bank.Completa las oraciones. Usa el banco de palabras.

I broke the figure into ___.Dividí la figura en ___.
I subtracted the areas because a piece was ___, so 140 minus 24 equals ___.Resté las áreas porque una parte fue ___, entonces 140 menos 24 es ___.

Build

Some language support

Write two connected sentences. Use because, so, or but.Escribe dos oraciones conectadas. Usa porque, entonces o pero.

My claim is ___.Mi afirmación es ___.
I know because ___.Lo sé porque ___.
So ___.Entonces ___.

Explain

Light language support

Write a claim, give math evidence, and explain your reasoning.Escribe una afirmación, da evidencia matemática y explica tu razonamiento.

My claim is ___.Mi afirmación es ___.
My math evidence is ___.Mi evidencia matemática es ___.
This proves ___ because ___.Esto demuestra ___ porque ___.

4. Check Your Explanation

I answered the question.Respondí la pregunta. I used math evidence: numbers, an equation, a model, or a comparison.Usé evidencia matemática: números, una ecuación, un modelo o una comparación. I explained how the evidence proves my answer.Expliqué cómo la evidencia demuestra mi respuesta. I used at least two math words.Usé por lo menos dos palabras matemáticas. I reread complete sentences and punctuation.Volví a leer mis oraciones completas y la puntuación.