Plane Geometry Flashcards
Three undefined term in geometry
•point
•line
•plane
a flat surface without thickness
Plane
It’s a closed plane figure bounded by straight line segments as sides with 3 or more angles
Polygon
Types of polygons
Convex and concave
A polygon with all interior angles less than 180 degree
Convex
A polygon with all interior angles greater than 180 degree
Concave
is the line segment connecting two nonconsecutive vertices of a polygon
Diagonal
is the angle between two consecutive sides of a polygon
Interior angle
is the angle subtended by any side and the center of the polygon.
Central angle
is the angle formed by the extension of any side of a polygon and the next adjacent side.
Exterior angle
Defined as the distance from the center of a regular polygon to the midpoint of its sides
Apothem
A plane figure with four straight sided
Quadrilaterals
Is a quadrilateral in which opposite sides are parallel and equal
Parallelogram
Is a quadrilateral with only one pair of opposite sides parallel
Trapezoid
is a quadrilateral in which all sides are equal but none of the angles is 90°
Rhombus