In brief: Angular houses are 1, 4, 7, and 10; succedent houses are 2, 5, 8, and 11; cadent houses are 3, 6, 9, and 12.
The three sets
The four angular houses begin at or contain the principal chart angles, depending on the house system: Ascendant, Imum Coeli, Descendant, and Midheaven. Traditional authors called the following houses succedent and the houses before the next angle cadent. Number the houses around a chart and the pattern repeats: angular 1, succedent 2, cadent 3; angular 4, succedent 5, cadent 6; and so on. The grouping describes a house’s structural place, not its zodiac sign.
Why house system matters
In a quadrant system, the four angular cusps coincide with the corresponding angles. Whole Sign houses start at sign boundaries, so a Midheaven can lie inside the ninth, tenth, or eleventh house instead of automatically marking the tenth cusp. Equal houses begin at the Ascendant degree and often put the Midheaven inside a house. A statement that a planet is “near an angle” should therefore give both its angular distance and the chosen house system.
How the distinction is used
Traditional astrology often treated angular placements as more capable of acting openly, succedent placements as sustaining or developing matters, and cadent placements as less directly placed for action. Those are interpretive conventions. They do not mean that a third-house planet is invisible or a tenth-house planet guarantees public success. Read the planet, its actual house, its aspects, and the question before assigning weight.
A worked reading step
Suppose a birth chart shows Venus in house 11. Eleven is succedent, following the angular tenth. First verify that the recorded time and location support the house assignment; a guessed birth hour can move house cusps. Then distinguish the positional claim—Venus falls in house 11—from a symbolic reading about relationships or alliances. If the house system is changed, check whether the placement remains in house 11 before carrying the same interpretation across charts.