49 terms

# Geometry definitions

#### Terms in this set (...)

point
exact location (looks like a dot)
line
straight path that goes on forever in both directions
line segment
part of a line that has a beginning and an end
ray
line with a beginning but no end
plane
flat surface that goes on forever in all directions
angle
2 rays that meet together at a common point
vertex
point where the 2 rays meet at
acute angle
an angle that is less than 90 degrees
obtuse angle
an angle that measures more than 90 degrees
right angle
an angle that measures exactly 90 degrees
straight angle
an angle that is exactly 180 degrees
complementary angles
angles who add up to 90 degrees
supplementary angles
angles who add up to 180 degrees
congruent
same shape, size
parallel lines
lines that are the same width apart, they don't get closer nor do they get farther apart
perpendicular lines
lines that intersect and make a 90 degree angle
skew lines
lines in different planes, they don't intersect and aren't parallel
interior angles
angles inside parallel lines-cut by a transversal
exterior angles
angles outside parallel lines-cut by a transversal
alternate interior angles
criss cross angles on the inside of parallel lines cut by a transversal
alternate exterior angles
criss cross angles on the outside of parallel lines cut by a transversal
corresponding angles
angles in the same locations on different lines
vertical angles
criss cross angles on the same line
transversal
line that intersects 2 or more parallel lines
polygon
simple closed figures with at least 3 sides
regular polygon
polygon with equal sided and equal length
triangle
3 sided polygon with 3 angles
4 sided polygon with 4 angles
pentagon
5 sided polygon with 5 angles
hexagon
6 sided polygon with 6 angles
heptagon
7 sided polygon with 7 angles
octagon
8 sided polygon with 8 angles
nonagon
9 sided polygon with 9 angles
decagon
10 sided polygon with 10 angles
acute triangle
has three acute angles
right triangle
triangle that has a right angle
obtuse triangle
has an obtuse angle
equilateral triangle
triabgle that has three sides that are congruent
isosceles triangle
triangle that has 2 congruent sides
scalene triangle
triangle that has no congruent angles
a polygon with 4 sides (simple closed figure with 4 sided and angles
parallelogram
is a quadrilateral with 2 pairs of parallel sides ( its sided are both parallel and congruent)
rectangle
a parallelogram that has 4 right angles ( a quadrilateral with 4 right angles)
rhombus
a parallelogram with 4 congruent sides (a quadrilateral with 4 congruent sides
square
parallelogram with 4 right angles and 4 congruent sides (a quadrilareral with 4 right angles adn 4 congruent sides; a rectangle with 4 congruent sides)
trapezoid
a quadrilareral with exactly one pair of parallel sides
concave polygon
polygon that has at least 1 concave angle (caves in)
convex polygon
polygon that has all convex angles (pushes out)
kite
polygon or a quadrilateral