*Quadrilateral scrapbook geometery*

!Jay-hoosey delpozo!9th

2-23-11

!Table of contents!

• Page 1• Page 2• Page 3• Page 4• Page 5• Page 6

• Irregular quadrilateral

• Parallelogram• Rhombus• Square • Rectangle• TRAPEZOID

Irregular quadrilateral• Def-A regular quadrilateral is

one with equal sides and equal angles, so it is a square.

• Example1-quadrilateral is a polygon with four sides

• Example2-the term quadrangle is used, by analogy with triangle

• Example3-Simple quadrilaterals are either convex or concave.

Parallelogram

. Def-parallelogram is a quadrilateral with two pairs of parallel sides.

Example1-parallelogram with four angles of equal size.

Example2-parallelogram with four sides of equal length

Example3-Adjacent angles are supplementary (add up to 180 degrees)

.

Rhombus • Def-a rhombus or rhomb is a

quadrilateral whose four sides all have the same length.

• Example1-The rhombus is often called a diamond.

Example2-Every rhombus is a parallelogram.

• Example3-Every rhombus has two diagonals connecting opposite pairs of vertices and two pairs of parallel sides.

Squares!• Def-This means that it

has four equal sides and four equal angles (90 degree angles, or right angles)

• Example1-A square is both a rhombus (equal sides) and a rectangle

• Example2-a square is a regular quadrilateral

• Example3-The diagonals of a square are equal

Rectangle• Def-In Euclidean plane

geometry, a rectangle is any quadrilateral with four right angles

• Example1-angles are not right angles.

• Example2-rectangles with opposite sides equal in length and equal angles that are not right angles

• Example3- Rectangles are involved in many tiling problems, such as tiling the plane by rectangles or tiling a rectangle by polygons.

Trapezoid• Def-four-sided figure with

one pair of parallel sides is referred to as a trapezoid

• Example1- The term trapezium has been in use in English since 1570,

• Example2-There is also some disagreement on the allowed number of parallel sides in a trapezoid

• Example3-Some authors define a trapezoid as a quadrilateral having exactly one pair of parallel sides,