Math Chapter 18 Flashcards
To learn the vocabulary of Chapter 18
A figure that can be rotated less than 360 degress around a central point and it looks the same
rotational symmetry
A figure that can be folded in half and it is the same on both sides
line symmetry
An angle less than 90 degrees
acute angle
Figures with the same shape and size.
congruent figures
A triangle with one obtuse angle
obtuse triangle
A closed plane figure where all points are the same distance form the center point.
circle
A tool used for measuring or drawing angles
protractor
A line segment that passes through the center of the circle and has both of its end points on the circle.
diameter
A _____ is a quadrilateral with two pairs of opposite sides that are parallel and congruent
parallelogram
A triangle that doesn’t have any congruent sides
scalene triangle
A _____ and a _____ have four right angles with opposite sides that are parallel and congruent
rectangle, square
A two demensional pattern that can be folded into a three-dimensional polyhedron
net
A repeating pattern of closed figures. There aren’t any gaps between the polygons.
tessellation
Lines that are not in the same plane, not parallel, and do not intersect
skew lines
A triangle where all of the sides are congruent
equalateral triangle
Two lines side by side that never touch
parallel lines
Part of a line between two endpoints.
line segment
A solid figure with faces that are polygons
polyhedron
A flat surface that extends forever in all directions. It is names with three points not on the same line.
plane
An angle that measures exactly 180 degrees
straight angle
_____ sides and _____ angles are in the same relative position in different figures.
corresponding, corresponding
A type of transformation where the figure slides to a new postion.
translation
A _____ is a quadrilateral with one pair of parallel sides
trapazoid
A closed figure with four sides and four angles
general quadrilateral
All the polygons that are flat surfaces of a solid figure
faces
What are the two categories of quadrilaterals?
parallelograms and trapezoids
A part of a line that begins at one end point and goes on forever in the other direction. It is named with tow points.
ray
The top or bottom of a prism
base
A polygon where all faces and angles are congruent
regular polygon
Figures that have the same shape but different sizes.
similar figures
A line segment with its end points on the circle. It does not pass through the center point of a circle.
chord
A _____ has four congruent sides and four right angles
square
A triangle with three acute angles
acute triangle
A type of transformation that is a turn. The figure turns to a new postion about a vertex, or point of rotation.
rotation
‘what does “intersect” mean?
to “cross”
This type of triangle has two congruent sides
isosoles triangle
A straight path in a plane that goes on forever in each direction. It is named with two points.
line
An angle that measures 90 degrees
right angle
A type of transformation where the figure is flipped over a line.
reflection
An angle that is measures more than 90 degrees but less than 180 degrees
obtuse angle
This triangle has a right angle
right triangle
The line where two faces meet
edge
A square can be both a __________ and a ___________.
rectangle, rhombus
A _____ is a polyhedron with only one polygon base. All the other faces are triangles that meet at a common vertex. The shape of its base names the figure.
pyramid
A _____ is a polyhedron that has two congruent and parallel polygons as bases.
prism
A _____ is a parallelogram with 4 congruent sides and no right angles.
rhombus
What are the two categories of parallelograms?
rectangles and rhombuses
An exact location in space, named with a letter.
point
2-D closed figures made of line segments. They are named by the numbers of their sides.
polygons
Two lines that intersect to form right angles
perpendicular lines
A movement of a figure to a new postion by a translation, reflection, or rotation
transformation
Two lines that cross at one point
intersecting lines
The point where three or more edges meet
vertex
