Geometry in the Real WorldBy Sam Spoonemore Block 1

Point

• An undefined term in geometry, it names a location and has no size.

Line (Segment)

• A part of a line that is bounded by two end points, and contains every point on the line between its end points.

Plane

• An undefined term in geometry, it is a flat surface that has no thickness and extends forever.

Angle

• A figure formed by two rays with a common endpoint.

Perpendicular Lines

• Lines that intersect at 90° angles.

Parallel Lines

• Lines in the same plane that do not intersect.

Triangle

• A three-sided polygon.

Right Triangle

• A triangle with one right angle.

Pentagon

• A five-sided polygon.

Hexagon

• A six-sided polygon.

Square

• A quadrilateral with four congruent sides and four right angles.

Rectangle

• A quadrilateral with four right angles.

Trapezoid

• A quadrilateral with exactly one pair of parallel sides.

Parallelogram

• A quadrilateral with two pairs of parallel sides.

Circle

• The set of points in a plane that are a fixed distance from a given point called the center of the circle.

Cylinder

• A three-dimensional figure with two parallel congruent circular bases and a curved lateral surface that connects the bases.

Sphere

• The set of points in space that are a fixed distance from a given point called the center of the sphere.

Octagon

• An eight-sided polygon.

Cube

• A prism with six square faces.

Hemisphere

• Half of a sphere.