A high-school astronomy: in which the descriptive, physical, and practical are combined .. (1859)
Mattison, Hiram, 1811-1868 · New York, Mason brothers · leaf 25
An Acute-angled Triangle is one having three acute angles. … An Equilateral Triangle has all three ofits sides equal. Equilateral, from the Latin cequus, equal, and lateralis, fromlatus, side. AN EQUILATERALTRIANGLE.
Astronomy
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