Section 1.1 Flashcards
Point
A dot with a capital letter (no dimension)
Line
A straight line that continues infinitely. The line can be named by two points or more by placing a line symbol
Plane
A flat surface that extends infinitely along its length and width.
Collinear Points
Points that lie on the same line
Coplanar Points
Points that lie on the same plane
Line Segment
Two points (endpoints) and all the points between that are collinear with the two points
(written as line AB)
Midpoint
A point on a line segment that is the same distance from both endpoints
Angle
Two rays that share a common endpoint (vertex)
Vertex
The endpoint of two rays
Ray
It is a bisector that bisects the two congruent angles in half
Adjacent
Angles that share a vertex and a side
Parallel
Lines in the same plane that never cross
Perpendicular
Lines that meet at 90 degrees angles
Right Angle
An angle that measures 90 degrees
Acute Angle
An angle that measures less than 90 degrees (0 degrees to 90 degrees)
Obtuse Angle
An angle that measures more than 90 degrees and less than 180 degrees (90 degrees to 180 degrees)
Complementary Angles
A pair of angles that sum to 90 degrees
Supplementary Angles
A pair of angles that sum to 180 degrees
Vertical Angles
A pair of angles that are opposite each other where 2 lines intersect
Linear Pair of Angles
Adjacent angles that lie on the same line
Polygon
A closed figure in a plane formed by connecting line segments endpoint to endpoint with each segment (side of a polygon) intersecting exactly two others.
What has three sides?
Triangle
What has four sides?
Quadrilateral
What has five sides?
Pentagon
What has six sides?
Hexagon
What has seven sides?
Heptagon
What has eight sides?
Octagon
What has nine sides?
Nonagon
What has ten sides?
Decagon
What has eleven sides?
Undecagon
What has twelve sides?
Dodecagon
Diagonal of a Polygon
A line segment that connects two nonconsecutive (not next to each other) vertices
Convex
No diagonals are outside the polygon
Concave
At least one diagonal is outside the polygon
Congruent
Equal sides
Parallel
Sides that are the same
Perpendicular
Sides that equal 90 degrees
Equilateral Polygon
Polygons with all congruent sides
Regular Polygon
Polygons with all congruent sides and angles (Equilateral and Equiangular)
Equiangular Polygon
Polygons with all congruent angles
Right Triangle
A triangle with exactly one right angle
Acute Triangle
A triangle with three acute angles
Obtuse Triangle
A triangle with one obtuse angle (Angle greater than 90 degrees)
Scalene Triangle
A triangle with three different side lengths (No congruent sides)
Equilateral Triangle
A triangle with three congruent sides
Isosceles Triangle
A triangle with (at least) two congruent sides
Trapezoid
A quadrilateral with exactly one pair of parallel sides
Kite
A quadrilateral with two pairs of same sides in a row
Parallelogram
A quadrilateral with two pairs of parallel sides
Rhombus
A quadrilateral with four congruent sides (Equilateral quadrilateral or Equilateral Parallelogram)
Rectangle
A quadrilateral with four right angles (Equiangular Parallelogram or Equiangular Quadrilateral)
Square
A quadrilateral with four right angles and four congruent sides (Equilateral and Equiangular Parallelogram; Regular Quadrilateral)
Chord
A line segment with both endpoints being ON the circle
Diameter
A chord that passes through the cent of a circle
Tangent
A line that intersects the circle exactly one time
Point of Tangency
The point on the circle that has a line intersects the circle one time
Secant
A line that intersects a circle at two points
Concentric circles
A circle with two or more circles with a common center. (Bullseye)
Circumscribed
A circle that has a shape inside it
Inscribed circle
A circle that is inside a shape
Semicircle
An arc of a circle whose endpoints are the endpoints of a diameter
Minor Arc
An arc of a circle that is smaller than a semicircle
Major Arc
An arc of a circle that is larger than a semicircle
