trapezium
Four-sided, irregular shape
A trapezium is a quadrilateral with one pair of parallel sides—or in British usage, a quadrilateral with no parallel sides at all.
The transatlantic meanings are essentially reversed, causing confusion in geometry classrooms.
In anatomy, the trapezium is a bone at the base of the thumb.
The trapezium articulates with the first metacarpal.
Hand-forearm connection
- boneHard skeletal tissue
- metacarpalLong bone in hand
- thumbShort opposable digit
- scaphoidCarpal bone, thumb-side
hand · carpus · articulation · ligament · tendon · joint · phalanges · radius
Quadrilateral with paired parallels
- rhombusEquilateral parallelogram
- rectangleFour-sided, all right angles
- squareRhombus with right angles
- verticesCorner points of shapes
sides · angles · diagonal · perimeter · area · convex · irregular · unequal
Traveling entertainment with performers
Deviating from normal patterns
- unequalNot the same
- lopsidedUnequally balanced
- skewedAsymmetrically shifted
- unbalancedLacking equilibrium or stability
nonparallel · oblique · uneven · slanted · tilted · angled · distorted · disproportionate
wrist
Hand-forearm connection
- boneHard skeletal tissue
- metacarpalLong bone in hand
- thumbShort opposable digit
scaphoid · hand · carpus · articulation · ligament · tendon · joint · phalanges · radius · ulna
parallelogram
Quadrilateral with paired parallels
- rhombusEquilateral parallelogram
- rectangleFour-sided, all right angles
- squareRhombus with right angles
vertices · sides · angles · diagonal · perimeter · area · convex · irregular · unequal · isosceles
circus
Traveling entertainment with performers
irregular
Deviating from normal patterns
unbalanced · nonparallel · oblique · uneven · slanted · tilted · angled · distorted · disproportionate
- bonesskull, femur, tibia, skulls, humerus
- shapescircle, square, triangle, rectangle, oval
- arm boneshumerus, radius, ulna, carpals, metacarpals
- quadrilateralsrectangle, square, rhombus, parallelogram, kite
- short bonescarpals, tarsals, capitate, lunate, scaphoid
- wrist anatomywrist, wrist joint, carpal bones, carpals, scaphoid