Geometry in the Real World

Geometry in the Real WorldBy: Amanda Granato

PointA point specifies only location; it has no length, width, or depth. We usually represent a point with a dot on paper

Line SegmentA line segment is the portion of a line lying strictly between two points.

PlaneA 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.

AngleA shape, formed by two lines or rays diverging from a common point (the vertex)

Perpendicular LinesTwo lines that intersect to form a 90 angle

Parallel LinesParallel lines are two lines in the same plane that never intersect

Trianglea geometric figure having three angles and three sides; any three-sided or three-cornered figure, area, object, part, etc.

Right TriangleA right triangle is a triangle with one right (90) angle

PentagonA polygon having five sides and five interior angles.

Hexagona six-sided polygon

Squarea plane figure having four equal sides and four right angles

Rectangle

a parallelogram with four right angles

Trapezoida quadrilateral with two parallel sides

Parallelograma quadrilateral whose opposite sides are both parallel and equal in length

CircleA plane curve everywhere equidistant from a given fixed point, the center

CylinderThe surface generated by a straight line intersecting and moving along a closed plane curve

SphereA three-dimensional surface, all points of which are equidistant from a fixed point

Isosceles TriangleAn 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.

EdgeAn edge is a line segment where two faces intersect.