Komposisi dan Dekomposisi Bangun Datar Matematika Kelas 4 Kurikulum Merdeka

Summary

This educational video explains the concepts of composition and decomposition of flat shapes using tangram. It introduces tangram as a puzzle consisting of five triangles, one square, and one parallelogram, which can be combined to form various patterns such as a praying person, a skater, or an airplane. Composition refers to combining shapes to create a new one, while decomposition involves breaking a shape down into its individual components. Through visual examples, viewers learn to both assemble and disassemble shapes, understanding how complex figures can be built or deconstructed into basic geometric forms.

Takeaways

• 😀 Tangram is a traditional mathematical puzzle known as the 'Chinese puzzle' and consists of seven pieces: 5 triangles, 1 square, and 1 parallelogram.
• 😀 The goal of the lesson is for students to learn how to assemble tangram pieces into various shapes and decompose shapes into simpler geometric figures.
• 😀 Tangram can be used to form various shapes such as people, animals, and even letters and numbers.
• 😀 The process of combining different flat shapes to form a new pattern is called 'composition' (komposisi).
• 😀 An example of composition is a tangram forming a shape of a praying person.
• 😀 Another example of composition is using tangram pieces to create a figure of a person skating.
• 😀 Decomposition (dekomposisi) is the reverse process, where a complex shape is broken down into its individual flat shapes.
• 😀 The lesson encourages students to identify the different flat shapes that make up a composite figure, such as triangles, trapezoids, parallelograms, squares, and rectangles.
• 😀 One exercise involves decomposing a shape of a tree into its constituent geometric shapes, including 5 triangles, 5 trapezoids, 2 parallelograms, 1 square, and 1 rectangle.
• 😀 The video emphasizes that composition is the combination of shapes, while decomposition is the disassembly or breakdown of shapes into simpler components.

Q & A

What is the purpose of this lesson on tangram?

The purpose of the lesson is to help students learn how to compose and decompose flat shapes using tangram pieces.

What is tangram and what are its components?

Tangram is an ancient puzzle consisting of seven pieces: five triangles, one square, and one parallelogram.

What are the two main concepts introduced in this lesson?

The two main concepts are 'composition' (the process of combining flat shapes) and 'decomposition' (the process of breaking down a shape into its components).

What is the difference between composition and decomposition in geometry?

Composition refers to the combining of smaller shapes to form a new shape, while decomposition refers to breaking a complex shape down into simpler individual shapes.

Can you provide an example of a composition using tangram?

An example of composition using tangram is creating the shape of a person praying, a figure skating, or even an airplane.

What shape is formed when decomposing a tree shape in the video?

The tree shape is decomposed into several individual flat shapes, including triangles, trapezoids, parallelograms, squares, and rectangles.

How many triangles are used to form the tree shape?

There are five triangles used in the decomposition of the tree shape.

What is the role of squares and rectangles in the decomposition of shapes?

Squares and rectangles are part of the decomposition process, and they help in breaking down complex shapes into more manageable parts.

What type of shape is a trapezoid, as mentioned in the video?

A trapezoid is a four-sided shape with one pair of parallel sides.

How can understanding composition and decomposition help in learning mathematics?

Understanding composition and decomposition helps students grasp how complex shapes are formed or broken down, aiding in spatial reasoning, problem-solving, and geometric thinking.