# Geometry Scrapbook

By:Hayden Mouser

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# Point

A point specifies only location; it has no length, width, or depth.

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# Line

A line has only one dimension: length. It continues forever in two directions (so it has infinite length), but it has no width at all. A line connects two points via the shortest path, and then continues on in both directions.

# 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.

# Intersecting Lines

Two or more lines that meet at a point are called *intersecting lines*.

# Parallel lines

Parallel lines are two lines in the same plane that never intersect. No matter where you measure, the perpendicular distance between two parallel lines is constant.

# Pentagon

A pentagon is a polygon with five sides.

# Hexagon

A 6-sided polygon (a flat shape with straight sides).

# Octagon

An octagon is a geometrical shape that contains eight sides and eight angles.

# Decagon

A polygon having ten angles and ten sides.

# Sphere

A three-dimensional shape that looks like a ball.

# Acute Angle

An angle that is less than 90°.

# Obtuse Angle

An angle that is greater than 90° but less than 180°.

# Right Angle

An angle that is 90° exactly.

# Square

A square is a regular quadrilateral, which means that it has four equal sides and four equal angles.

# Rectangle

A square is a regular quadrilateral, which means that it has four equal sides and four equal angles.

# Trapezoid

A trapezoid is a quadrilateral that has one pair of opposite sides that are parallel.

# Rhombus

A rhombus is a quadrilateral that has all four sides congruent.

# Pyramid

A pyramid is a polyhedron formed by connecting a polygonal base and a point, called the apex.

# Cube

A solid with six congruent square faces.

# Triangle

The plane figure formed by connecting three points not in a straight line by straight line segments; a three-sided polygon.

# Circle

A circle is a shape with all points the same distance from its center.

# Horizontal Line

A horizontal line is one which runs left-to-right across the page.

# Vertical Line

A vertical line is one which runs up and down the page.

# Parallel Planes

Planes that never intersect each other.

# Cone

A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.