1. A dilatation is a type of transformation in geometry that changes the size of a shape but keeps its shape the same. 2. Imagine you have a small triangle, and you want to make a bigger one just like it. Dilatation does exactly this: it stretches or shrinks the shape. 3. It has two important parts: a center and a scale factor. 4. The center is a point that stays fixed, and every point of the shape moves closer to or farther from this center. 5. The scale factor tells us how much the shape is stretched or shrunk. 6. If the scale factor is greater than 1, the shape gets bigger. 7. If the scale factor is between 0 and 1, the shape gets smaller. 8. For example, if a scale factor is 2, every side of the shape becomes 2 times longer than before. 9. The shape looks exactly like the original, just bigger or smaller, with all angles staying the same. 10. This is useful to understand how objects scale up or down without changing their overall structure.