Point A point specifies only location; it has no length, width, or depth. We usually represent a point with a dot on paper
Line Segment A line segment is the portion of a line lying strictly between two points.
Plane A plane is a flat, two-dimensional object. We often represent a plane by a piece of paper, a blackboard, or the top of a desk. In fact, none of these is actually a plane, because a plane must continue infinitely in all directions and have no thickness at all. A plane can be defined by two intersecting lines or by three non-collinear points.
Angle A shape, formed by two lines or rays diverging from a common point (the vertex)
Perpendicular Lines Two lines that intersect to form a 90° angle
Parallel Lines Parallel lines are two lines in the same plane that never intersect
Triangle a geometric figure having three angles and three sides; any three-sided or three-cornered figure, area, object, part, etc.
Right Triangle A right triangle is a triangle with one right (90°) angle
Pentagon A polygon having five sides and five interior angles.
Hexagon a six-sided polygon
Square a plane figure having four equal sides and four right angles
Rectangle a parallelogram with four right angles
Trapezoid a quadrilateral with two parallel sides
Parallelogram a quadrilateral whose opposite sides are both parallel and equal in length
Circle A plane curve everywhere equidistant from a given fixed point, the center
Cylinder The surface generated by a straight line intersecting and moving along a closed plane curve
Sphere A three-dimensional surface, all points of which are equidistant from a fixed point
Isosceles Triangle An isosceles triangle is a triangle with two equal sides.
Angle Bisector An angle bisector is a ray that cuts the angle exactly in half, making two equal angles.
Edge An edge is a line segment where two faces intersect.