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
is a quadrilateral in which pairs of opposite sides are parallel and equal and each angle is 90°.
Rectangle
quadrilateral with four equal sides and four right angles.
Square
Is the set of all points in a plane that are the same distance from a fixed point called the center.
Circle
is a line segment joining the center to a point on a circle.
Radius
is a chord through the center of the circle. twice the radius.
Diameter
one of the two possible arcs determined by the endpoints of a diameter, taking its midpoint as centre.
Semicircle
is any connected part of a circle.
Arc
the distance around the circle
Circumference
is an arc that is less than the semi circle
Minor arc
is the arc that is greater than a semi-circle
Major arc
is a segment joining two points of the circumference
Chord
is a line that intersects the circle at two points
Secant
is a line that touches the circle at one and only one point.
Tangent
Is an angle formed by two radius
Central angle