## 18.3 SQ Episode 029 – Angles in Quilting: Part B Quadrilaterals

August 13, 2011Podcast Feed

Now we’re looking at 4 sided figures in quilting – Quadrilaterals!

We have lots of kinds of Quadrilaterals from geometry class

Prallelogram Family

- Square
- Rectangle
- Rhombus
- Diamonds!
- Parallelograms

Other Quads

- Kite
- Trapezoid
- isocelese trapezoid
- regular trapezoid
- Random Shaped Quadrilaterals

Squares

- all 90 degree angles
- all equal sides
- vertical, horizontal and diagonal symmetry
- is a rectangle
- is a rhombus
- is a parallelogram
- usually no bias edges

Rectangles

- all 90 degree angles
- opposite sides are equal length
- opposite sides are parallel
- vertical & horizontal symmetry
- is a paralellogram
- usually no bias edges

(green is squares, yellow is rectangles)

Rhombus

- all equal sides
- opposite sides are parallel
- diagonal symmetry
- is a parallelogram
- potentially some bias on 2 sides usually
- quilters call these diamonds

Parallelogram

- opposite sides are equal length
- opposite sides are parallel
- no symmetry necessarily unless special case above
- potentially some bias on 2 sides usually

Kite

- adjacent sides are equal length
- opposite angles are equal
- diagonal symmetry one direction
- lots of bias edges
- one definition could make a kite = a rhombus
- one definition says that the shorter length does not equal the longer length

(dark red = parallelogram, pink = rhombus(diamond), blue = kite)

Trapezoid

- one set of opposite sides are parallel
- no particular symmetry
- cut a corner off a rectangle or square
- created from strip sets

Isosceles Trapezoid

- adjacent angles are equal to each other
- one set of opposite sides are equal length
- symmetry along one axis
- created from strip sets and/or isosceles triangles

(trapezoid = black, both isosceles and regular)

Four sided quilt patches are everywhere!

Crossing the Streams is ‘BAD’.

If you like exploring 2D figures, and you like books, and you like podcasts, check out Flatland on CraftLit.

Ecosystem notebook from Barnes N Noble

Music

Freesound.org

(This is funny too, not in episode)

Mevio’s Music Alley

- Square Peg by The Gentleman Callers
- Temptation by Emma Wallace

[…] These blocks provide lots of challenges to piecing. These shapes are not typically pieced the same way as triangles and quadrilaterals. […]

by 18.7 SQ Episode 030 – Angles in Quilting: Part C Polygons « Scientific Quilter August 21, 2011 at 12:50 pm