Symmetric Plane Figures

(Adapted from Taxon, 1962)

Length:Width

12:1

6:1

3:1

2:1

3:2

6:5

1:1

5:6

2:3

1:2

1:3

1:6

1:12

Elliptic
With widest axis at midpoint of structure and with margins symmetrically curved

narrowly elliptic

elliptic

widely elliptic

circular

oblate


transversely elliptic


narrowly transversely elliptic

Oblong
With widest axis at midpoint of structure and with margins essentially parallel

linear


narrowly oblong or ovate


oblong

widely oblong

square

transversely widely oblong


transversely oblong


narrowly transversely oblong

transversely linear

Ovate
With widest axis below middle and with margins symmetrically curved; egg-shaped

lanceolate

ovate

widely ovate

very widely ovate

widely depressed ovate

depressed ovate

Obovate
Inversely ovate

oblanceolate

obovate

widely obovate

very widely obovate

widely depressed obovate

depressed obovate

Rhombic
With widest axis at midpoint of structure, and with straight margins; elliptic but margins straight and middle angled

narrowly rhombic

rhombic

widely rhombic

quadrate rhombic

widely transversely rhombic

transversely rhombic

narrowly transversely rhombic

Trullate
With widest axis below middle and with straight margins; ovate but margins straight and angled below middle, trowel-shaped

narrowly trullate

trullate

widely trullate

very widely trullate

widely depressed trullate

transversely depressed trullate

Obtrullate
Inversely trullate

narrowly obtrullate

obtrullate

widely obtrullate

very widely obtrullate

widely depressed obtrullate

transversely depressed obtrullate

Triangular
With three sides and three angles

linear triangular

narrowly triangular

triangular

widely deltate

deltate

shallowly deltate

shallowly triangular

very shallowly triangular

Obtriangular
Inversely triangular

linear obtriangular or narrowly cuneate

cuneate

obtriangular or widely cuneate

widely obdeltate

obdeltate

shallowly obdeltate

shallowly obtriangular

very shallowly obtriangular