VOCABULARY

Rigid Transformations

A transformation that does not alter the size or shape of a figure; rotations, reflections, and translations are all rigid transformations.

https://www.youtube.com/watch?v=V09tgWxhYbI

Similar

Figures with the same shape but not necessarily the same size.

Congruent

Two or more images with the same size and shape.

Coordinate Plane

Two-dimensional plane formed by the intersection of a vertical line called y-axis and a horizontal line called x-axis.

X-axis

The line on a graph that runs horizontally (left-right) through zero.

Y-axis

The line on a graph that runs vertically (up-down) through zero.

Coordinates Or Ordered Pair

The x-coordinate is the first number in an ordered pair; it represents the distance to move right or left from the origin.

The y-coordinate is the second number in an ordered pair; it represents the distance to move up or down from the origin.

Quadrants

The x- and y-axes divide the coordinate plane into four regions. Each region is called a quadrant.

Origin

The point at which the x-axis and the y-axis intersect on the coordinate plane; (0, 0).

Translation

A type of rigid transformation that is a vertical or horizontal slide of a shape.

Rotation

A type of rigid transformation that is a turn around a fixed point called the center of rotation.

Reflection

A type of rigid transformation that is a 'flip' of a figure over the x-axis and y-axis.

Dilation

A type of rigid transformation that produces an image that is the same shape as the original, but is a different size; an enlargement or reduction of a figure.

Clockwise

The direction in which the hands of a clock rotate.

Counter-Clockwise

The direction opposite to that of the normal rotation of the hands of a clock; not clockwise.

Scale Factor

The ratio used to enlarge or reduce similar figures.

Center of Dilation

A fixed point in the plane about which all points are enlarged or reduced it is the only non-changing point under a dilation.