Several parts combine into one character.

形 is a phonetic-semantic compound: 开 (kāi, "open frame / level") on the left provides the sound and a sense of structural form, while 彡 (shān, "feathery streaks / pattern marks") on the right indicates the visible decoration on a surface. The composite reads as "what manifests as patterned outline along a frame" — shape, form, the visible arrangement of an object. The decorative-stroke radical 彡 anchors a small but visually rich family: 形 (shape), 影 (shadow / silhouette), 彩 (color / radiance), 彫 (carve / engrave) — all about what appears on the surface as visible pattern.

Korean reading "hyeong." This single character forms the backbone of Korean mathematical, linguistic, and philosophical vocabulary: 形態 (hyeongtae, form / morphology), 圓形 (wonhyeong, circle), 四角形 (sagakhyeong, quadrilateral / square), 變形 (byeonhyeong, deformation / variation), 形容詞 (hyeongyongsa, adjective — a modifier that "shapes / describes"), 形而上 (hyeongisang, "above form" = metaphysical, from Confucian classics). When Korean students study geometry, grammar, or philosophy, 形 appears constantly.

Mandarin xíng, 2nd tone. 形状 (xíngzhuàng, shape), 形容 (xíngróng, to describe), 圆形 (yuánxíng, circular), 形成 (xíngchéng, to take shape / form), 形势 (xíngshì, situation / circumstances). Used freely across abstract and concrete contexts in modern Mandarin.

Japanese has two on-readings reflecting different historical layers. ケイ (kei) — 形態 (keitai, form — also the root of 携帯 keitai meaning "mobile / portable" but that's a different etymology), 正方形 (seihōkei, square), 形容詞 (keiyōshi, adjective). ギョウ (gyō) — 人形 (ningyō, doll — literally "person-shape"), 形相 (gyōsō, appearance / aspect — philosophical term). The kun-readings make a delicate distinction: かた (kata) tends toward "the abstract pattern / mold / formal type" — 型 with a different kanji is also kata, meaning "mold / fixed form." かたち (katachi) leans toward "the manifest outer shape." 形 (katachi) and 型 (kata) are heard alongside each other in martial arts contexts where kata refers to the prescribed form of movement.

Memory aid: a frame (开) plus surface streaks (彡) — the visible patterning of structure is shape.