Unit 5

• 8.G.A.1.a Verify experimentally the properties of rotations, reflections and translations: lines are taken to lines, and line segments to line segments of the same length
• 8.G.A.1.b Verify experimentally the properties of rotations, reflections and translations: angles are taken to angles of the same measure
• 8.G.A.1.c Verify experimentally the properties of rotations, reflections and translations: parallel lines are taken to parallel lines
• 8.G.A.2 Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them.
• 8.G.A.3 Describe the effect of dilation, translations, rotations, and reflections on two-dimensional figures using coordinates.
• 8.G.A.4 Understand that a two-dimensional figure is similar to another if the second can be obtained from the first by a sequence of rotations, reflections, translations, and dilation; given two similar two-dimensional figures, describe a sequence that exhibits the similarity between them.
• 8.G.A.5 Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.

Alternate Exterior: For two lines intersected by a transversal, a pair of angles that lie on opposite sides of the transversal and outside the other two lines.

Alternate Interior: For two lines intersected by a transversal, a pair of nonadjacent angles that lie on opposite sides of the transversal and between the other two lines.

Congruent: Having the same size and shape; the symbol for congruent is ≌.

construct:

Coordinate Plane: A plane formed by the intersection of a horizontal number line called the x-axis and a vertical number line called the y-axis.

Corresponding: The relationship between two or more objects that are matched

*Corresponding Angles: For two lines intersected by a transversal, a pair of angles that lie on the same side of the transversal and on the same sides of the other two lines.

*Dilation: A transformation that enlarges or reduces a figure.

Dimension: The length, width, or height of a figure.

Horizontal: Left-to-right

*Image: A figure resulting from a transformation.

*Non-rigid: A series of transformations which includes a dilation. The image and pre-image are not congruent.

Origin: The point where the x-axis and y-axis intersect on the coordinate plane; (0, 0).

Parallel Lines: Lines in a plane that do not intersect.

*Pre-image: The original figure in a transformation.

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

Reflection: A transformation of a figure that flips the figure across a line.

*Rigid: A series of translations, reflections and rotations. The image and pre-image are congruent

Rotation: A transformation in which a figure is turned around a point

*Similar: Figures with the same shape but not necessarily the same size.

Transformation: A change in the size or position of a figure.

*Transformation Notations: An image following a transformation is denoted with a ‘ following each point of the figure

Translation: A movement (slide) of a figure along a straight line.

Transversal: A line that intersects two or more lines.

Vertical: up-and-down

X-axis: The horizontal axis on a coordinate plane.

Y-axis: The vertical axis on a coordinate plane.