12.2 Solving Transformation Problems (MATH)

You already know that a shape can be transformed by a reflection, rotation or translation. When a shape undergoes any of these three transformation it only changes its position. Its shape and size stay the same. Under these three transformations, an object and its image are always congruent.
When you reflect a shape on a coordinate grid you need to know the
equation of the mirror line.
All vertical lines are parallel to the y-axis and have the equation x = 'a number'.
All horizontal lines are parallel to the x-axis and have the equation y = 'a number'.
Some examples are shown on the grid on the right.
When you rotate a shape on a coordinate grid you need to know the
coordinate of the centre of rotation, and the size and direction of the turn.
When you translate a shape on a coordinate grid, you can describe its movement with a column vector.

This is an example of a column vector : (4,5)

The left number state how many units to move the shape right (positive number) or left (negative number). The right number states how many units to move the shape up (positive number) or down (negative number).

For example:  (4,5)  means 'move the shape 4 units right and 5 units up'
                      (-2,-3)  means 'move the shape 2 units left and 3 units down'.


You can use any of these three transformation to solve all sorts of problems.

You may check this website if you still didn't understand:

http://www.mathsisfun.com/geometry/transformations.html