Things You Need to Know
- A transformation is when a point or a shape is changed in some way.
- There are four main types of transformation:
- Translations
- Dilations
- Reflections
- Rotations
- A translation is simply a change in the location of a shape.
- Usually done with an ordered pair. The first number tells you how much left/right to move the object, and the second number tells you how much up/down to move the object.
- Example: (4, -5): move right 4, down 5.
- Example: (-6, 2): move left 6, up 2.
- A dilation is a change in the size of a shape.
- This is done with a "scale factor". Use the scale factor to multiply all sides/dimensions of the object.
- If the scale factor is greater than 1, we make the shape that many times bigger.
- If less than 1, the shape will become smaller.
- Reflections are when a object is flipped across an axis of reflection.
- If the line is y = ___, it will be a horizontal line.
- If the line is x = ___, it will be a vertical line.
- If the line is y = x, it is a diagonal line and you just need to swap your x and y coordinates to get the new coordinates.
- Rotations are when an object is rotated about a point. Almost always the origin.
- If you have a point (x, y) that you're rotating:
- 90 degrees clockwise: new point is (y, -x)
- 180 degrees clockwise: new point is (-x, -y)
- 270 degrees clockwise: new point is (-y, x)
- If you have a point (x, y) that you're rotating:
Interactive Activities
Sample Problems
Class Notes