Trine

At 120 degrees, a third of the wheel, two points sit four signs apart and usually in signs of one type. Raphael's Guide 1877 notes that fiery signs trine fiery signs and that the same runs through the earthy, airy and watery groups. Ptolemy, in Ashmand's 1822 translation, calls the shape harmonious on the same logic of matching signs, without using those four element names.

It is the friendliest aspect in the older lists, and that very ease drew a complaint. Heindel 1919 says a chart with only good aspects would give a dull existence and prefers one with tension. Modern popular astrology tends to agree and describes the trine as talent that can be taken for granted.

The calculator allows 7 degrees for this angle, the same margin as its square. Orb figures are this site's own choice: the older books give margins by planet, Heindel a flat 6 degrees, and no number on the page has authority behind it.