In astrology the term angle is usually used to refer to one of the four angular houses, and especially to the specific degree associated with that house.
The four angles and the houses associated with them are:
1) The ascendant and the 1st house.
2) The midheaven and the 10th house.
3) The descendant and the 7th house.
4) The imum coeli and the 4th house.
When a planet is in one of these four houses in a chart it is said to be “in an angle” or “angular“.