47. Geometric transformations

Página 47

The Geometric Transformations are operations that change the position, orientation or size of a figure in the plane. They are fundamental to the study of geometry and frequently appear in Enem questions. In this context, we will address three main types of geometric transformations: translation, rotation and homothety.

To begin with, Translation is a geometric transformation that moves a figure from one place to another without changing its shape or size. Imagine a point A that is shifted to a new point A'. The translation that takes A to A' is the same for all points in the figure. Therefore, the figure keeps the same shape and size, only its position is changed. In mathematical terms, we can say that translation is a vector operation that adds a constant vector to each point of the figure.

Then Rotation is a geometric transformation that rotates a figure around a point called the center of rotation. The amount of rotation is measured in degrees. For example, a 180 degree rotation around a point rotates the figure so that it is upside down. Rotating preserves the figure's size and shape, but changes its orientation. Mathematically, rotation is a complex operation involving trigonometry and rotation matrices.

Finally, Homothety is a geometric transformation that changes the size of a figure without changing its shape. The homothety center is a fixed point and each point in the figure is moved along the line connecting it to the homothety center. The distance of each point from the center of homothety is multiplied by a constant factor called the homothety ratio. If the homothety ratio is greater than 1, the figure is enlarged. If the homothety ratio is less than 1, the figure is reduced. The homothety preserves the shape of the figure, but changes its size.

These geometric transformations can be combined to produce more complex transformations. For example, a figure can first be translated, then rotated and finally homothetized. Furthermore, geometric transformations have many practical applications. They are used in graphic design to move, rotate and resize objects. They are also used in physics to describe motions of particles and rigid bodies.

In summary, geometric transformations are an important topic in mathematics and in Enem. They allow manipulating figures in different ways and have many practical applications. To be successful in the Enem questions about geometric transformations, it is important to understand the basic concepts of translation, rotation and homothety, and be able to apply them to concrete problems.

Studying for the ENEM can be challenging, but with the right understanding of the concepts and lots of practice, you can master the math and do well on the test. Remember that mathematics is a subject that requires understanding and practice. So keep studying, practice problems, and don't be afraid to ask for help if you need it. Good luck with your studies!

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