Geometry Unit 1 Vocabulary Flashcards
(27 cards)
Line
Straight, contains infinite amount of points and extends infinitely in opposite directions
Point
A location represented by a do. The intersection of 2 lines.
Plane
Flat, 2 dimensional surface that extends infinitely in all directions. Any 3 non-collinear points make a plane. Named with 1 letter or 3 points.
Segment
A part of a line. Segments have 2 end lines and are named with them.
Ray
A part of a line that starts a point and extends infinitely in 1 direction,
Angle
A figure formed by 2 rays with common end points p.
Parallel lines
2 lines on the same plane that never intersect
Perpendicular lines
Lines that intersect to form 4 right angles
Congruence
The relationship between figures having the same shape and same size symbol.
Acute angles
Less than 90 degrees
Obtuse angle
Less than 180 degrees but more than 90 degrees
Straight angle
Exactly 180 degrees
Right angle
Exactly 90 degrees
Rigid motion
The action of taking an object and moving it without altering its shape or size: corresponding angles and sides stay congruent
Non Rigid Motion
Size is changed but shape isn’t
Reflection
Mirror image, a flip over a line of symmetry
Translation
Slide, glide
Rotation
Twist, turn about a point clockwise vs. counterclockwise
Lines of symmetry
Cutting something in half equally
Rotational symmetry
How many times you turn the figure and it is in the same position.
Composition
2 transformations applied to an object.
Motion rule for 270 degrees or 90 clockwise
Y, -X
Motion rule for 180 degrees
-X, -Y
Motion rule for Y axis
-X, Y
