 Deer Valley Middle School
 Glossary Terms

Unit 4
combining like terms a mathematical process used to simplify an expression to add or subtract polynomials
constant term doesn't change when x changes; i.e., 5x8; 5x+2system of equations a set of equations where you want to find a solution that makes all the equations true at the same time; i.e., x+y=5; 2xy=2; solution: (1,4)
Unit 3
linear relationship a relationship between two quantities that graphs a line
slope rate of change; constant rate;vertical
horizontal
solution to an equation with two variables any ordered pair (x,y) that can be used in place of the variables to make the equation true
vertical intercept the point where the graphed line crosses the vertical axis; "yintercept"Unit 2
center (of dilation)  (lesson 3) The point (center) from which a dilation occurs.
dilation  (lesson 2) A dilation occurs when a figure changes size but not shape (shrinks or enlarges) by a scale factor. A dilation must have a center from which the dilation occurs.scale factor  (lesson 1) The scale factor is the multiplier used to dilate a figure.
similar  (lesson 6) On figure is similar to another if there is a sequence of rigid transformations and dilations that moves the ifrst figure so that it fits exactly over the second.
slope  (lesson 10) The slope of a line is the quotient of the the vertical distance and the horizontal distance between any two points on the line.Unit 1
alternate interior angles  (lesson 14) Interior angles that are made by a transversal crossing two parallel lines. They are the angles that lie between the parallel lines, not outside them, and are on opposite sides of the transversal.
clockwise  (lesson 2) An object rotating clockwise is turning the same way that the hour or minute hand goes around a clock.
congruent  (lesson 11) One figure is congruent to another if there is a rigid transformation (or a sequence of translations, rotations and reflections) that moves the first figure so that it fits exactly over the second.
corresponding (angles, distances, parts, points, sides)  (lesson 17) Are the image (copy) angles, distances, parts, points or sides of the original shape.
counterclockwise  (lesson 2) An object rotating counterclockwise is turning the opposite way tht the hour or minute hand goes around a clock.
image  (lesson 2) The copy of an original shape.
reflection  (lesson 2) The mirror image (copy) of a figure, always reflected over a "line of reflection".
rigid transformation  (lesson 7) When you move a figure (transform) without changing (rigid) its size or shape. Rotations, reflections and translations are called "rigid transformations" because they move a figure (transform) without changing its size or shape (rigid).
rotation  (lesson 2) When you move a figure in a circular direction. A rotation will always have three elements: direction (clockwise/counterclockwise), distance (measured by degrees) and a center. Example: Triangle A rotated 54g clockwise around center O to get triangle B.
sequence of transformations  (lesson 4) A set of translations, rotations, reflections or dilations that move an original figure in a particular order resulting in a final figure.
straight angle  (lesson 15) Two rays that make an angle that forms a straight line. The angle is called a straight angle, and always equals 180g.
transformation  (lesson 4) A transformation is a translation, rotation, reflection, or dilation or combination of these. Note: Rigid Transformations are only reflections, rotations or translations.
translation  (lesson 2) A translation is when you move a figure by "sliding" up, down, left, right, or diagional. A translation always has direction and distance.
transversal  (lesson 14) A transversal to two parallel lines is a line that cuts across them, intersecting each one.
vertical angles  (lesson 9) a pair of vertical angles is a pair of angles that are across from each other at the point where two lines intersect. They will always be congruent to each other.