Getting to know the eight trigrams
Each hexagram contains two groups of three lines. Learning these eight possible groups makes a six-line figure easier to recognize and describe.
Read three lines from the bottom
A trigram has three lines, each either broken yin or solid yang. Three positions with two choices each give eight possible patterns. A hexagram uses one trigram below another, making 8 × 8 = 64 combinations.
The order matters. The bottom three lines of a hexagram form its lower trigram. Lines 4, 5, and 6 form its upper trigram, and you read those three from their own bottom upward too. The three-coin guide shows how the six lines are built.
In the table, the line sequences run from bottom to top. They are written out rather than stacked so you can check every position without mistaking the first item for the top line.
The eight patterns
| Name | Chinese | Lines, bottom to top | Nature image |
|---|---|---|---|
| Qian | 乾 | Solid, solid, solid | Heaven |
| Kun | 坤 | Broken, broken, broken | Earth |
| Zhen | 震 | Solid, broken, broken | Thunder |
| Kan | 坎 | Broken, solid, broken | Water |
| Gen | 艮 | Broken, broken, solid | Mountain |
| Xun | 巽 | Broken, solid, solid | Wind |
| Li | 離 | Solid, broken, solid | Fire |
| Dui | 兌 | Solid, solid, broken | Lake |
These nature images appear in the classical Discussion of the Trigrams, Shuo Gua. The text also gives other associations, so this table is a starting point, not an exhaustive dictionary. Xun, for example, is associated with wood as well as wind.
The images offer a vocabulary for reading: thunder suggests movement, mountain suggests stopping, and wind suggests entering or penetrating. English descriptions vary across translations. Keep the actual line pattern and Chinese name in view when comparing books.
Put a lower and upper trigram together
Take fire below mountain. The lower sequence is solid, broken, solid; above it comes broken, broken, solid. This makes hexagram 22, Bi. Its classical Image describes fire at the foot of the mountain, giving the combination a setting of its own.
Swap their places and you get a different figure: mountain below fire is hexagram 56, Lü. The same two trigrams can therefore belong to different hexagrams. Their placement is part of the pattern, not a detail you can omit.
This is also why a short label such as “fire means passion” is too narrow for interpreting a whole cast. Read the hexagram's own Judgment and Image before making a connection to your question.
Trigrams do not select the changing lines
A trigram shows which lines are yin or yang. By itself, it does not tell you whether a solid line came from 7 or 9, or whether a broken line came from 6 or 8. The saved coin totals determine which lines move.
Two readings can share the same lower and upper trigrams but have different changing lines. Use the trigrams to recognize the primary figure, then use the totals to follow its changes. You can practise by choosing a figure in the hexagram library, covering its name, and identifying the lower group before the upper one.