A high-school astronomy: in which the descriptive, physical, and practical are combined .. (1859)
Mattison, Hiram, 1811-1868 · New York, Mason brothers · leaf 27
or small, are supposed to bedivided into 360 equal parts, called degrees ; each degreeinto 60 equal parts, called minutes/ and each minuteinto 60 equal parts, called seconds. They are markedrespectively thus: Degrees (°), minutes (), seconds (). Equilateral? (Derivation?) Isosceles? (Derivation?)… … PARTS OF A CIRCLE. To save the trouble of dividing a circle into 300°, in order to measure the degreesof an angle, we make use of an instrument called a Protractor. It consists of a semi-circle of silver or brass, divided into de-grees, as represented in the inclosed figure.To measure an angle, as…
Astronomy
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