3-2 Transformations Explained
Key Concepts
1. **Translation**: Moving a shape without rotating or changing its size.
2. **Rotation**: Turning a shape around a fixed point.
3. **Reflection**: Flipping a shape over a line.
Detailed Explanation
Translation
Translation involves moving a shape from one position to another without changing its orientation or size. For example, if you slide a triangle 3 units to the right and 2 units up, it is a translation.
Rotation
Rotation is the process of turning a shape around a fixed point. The amount of turning is measured in degrees. For example, rotating a square 90 degrees clockwise around its center is a rotation.
Reflection
Reflection involves flipping a shape over a line, creating a mirror image. For example, reflecting a triangle over the y-axis will create a new triangle that is a mirror image of the original.
Examples
Example 1: Translate the triangle with vertices (1, 2), (3, 4), and (5, 2) 4 units to the right and 3 units down.
Solution: Each vertex is moved 4 units to the right and 3 units down:
(1 + 4, 2 - 3) = (5, -1)
(3 + 4, 4 - 3) = (7, 1)
(5 + 4, 2 - 3) = (9, -1)
New vertices: (5, -1), (7, 1), (9, -1)
Example 2: Rotate the square with vertices (1, 1), (3, 1), (3, 3), and (1, 3) 180 degrees around the origin.
Solution: Each vertex is rotated 180 degrees around the origin:
(1, 1) → (-1, -1)
(3, 1) → (-3, -1)
(3, 3) → (-3, -3)
(1, 3) → (-1, -3)
New vertices: (-1, -1), (-3, -1), (-3, -3), (-1, -3)
Example 3: Reflect the triangle with vertices (2, 3), (4, 5), and (6, 3) over the x-axis.
Solution: Each y-coordinate is multiplied by -1:
(2, 3) → (2, -3)
(4, 5) → (4, -5)
(6, 3) → (6, -3)
New vertices: (2, -3), (4, -5), (6, -3)
Analogies
Think of translation as sliding a piece of paper across a table. Rotation is like spinning a coin on a flat surface. Reflection is akin to looking at your reflection in a mirror.
Practical Application
Understanding transformations is essential in various fields such as computer graphics, architecture, and engineering. It helps in designing and analyzing shapes accurately.