This word had been used since the 1870s in the meaning 'the aspect from which a matter is considered'
(The old stagers...the men who knew all the angles, who had great experience—Nevil Shute, 1944)
, often with a defining word: the
Old English (up to 1150)D gives examples of statistical angles, selling angles, and propaganda angles. Examples:
For US television...competition for the same audience within the same time-slot drives producers and planners to look for the new exploitation angle which will differentiate their product within the market—Screen, 1991
He is always on the alert for a new angle, always individual in expression—Art Newspaper, 1992.
In more formal English,
standpoint is a better word to use.