Books Books When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is called a right angle; and the straight line which stands on the other is called a perpendicular to it. A course of geometrical drawing - Page 2
by William Schofield Binns - 1861 ## Practical Arithmetic, by Induction and Analysis

Joseph Ray - Arithmetic - 1885 - 350 pages
...stands on another so that it makes with it two equal angles, each of Right angle. Hisht these angles is a RIGHT ANGLE; and the straight line which stands on the other is said to be PERPENDICULAR to it, or at RIGHT ANGLES to it. A/ obt«se /Acute 3. An OBTUSE ANGLE is greater... ## The First Six Books of the Elements of Euclid: And Propositions I-XXI of ...

Euclid, John Casey - Euclid's Elements - 1885 - 340 pages
...adjacent angles at both sides of itself equal, each of the angles is called a right angle, and the line which stands on the other is called a perpendicular to it. D Hence a right angle is equal to its supplement. xv. An acute angle is one which is less than a right... ## The first six books of the Elements of Euclid, and propositions i.-xxi. of ...

Euclides - 1885 - 340 pages
...adjacent angles at both sides of itself equal, each of the angles is called a right angle, and the line which stands on the other is called a perpendicular to it. Hence a right angle is equal to its supplement. xv. An acute angle is one which is less than a right... ## Elementary Physiography: An Introduction to the Study of Nature

John Thornton - Physical geography - 1888 - 266 pages
...290. The Measurement of Angles. — Euclid gives the following definition of a right angle : — ' When a straight line standing on another straight...stands on the other is called a perpendicular to it.' We find it convenient for the purposes of angular measurement to divide the right angle into smaller... ## The Harpur Euclid: An Edition of Euclid's Elements

Edward Mann Langley, W. Seys Phillips - 1890 - 538 pages
...a reason for Euclid having chosen the method of Prop. 10 instead of it. See Note 2 on Prop. 9. DEF. 10. — When a straight line standing on another straight...and the straight line which stands on the other is said to be perpendicular, or at right angles, to it. The symbol for ' perpendicular 'is x r. The student... ## The Elements of Plane and Solid Geometry ...

Edward Albert Bowser - Geometry - 1890 - 414 pages
...said to bisect the angle between the non-coincident sides BA and BE. Fig. 6 Fig. 7 0 Fig. 8 O Fig. 9 called a right angle; and the straight line which stands on the other is said to be perpendicular or at right angles to it. Thus, if the adjacent angles AOC and BOC are equal... ## The Elements of Euclid: Viz. the First Six Books, Together with the Eleventh ...

Euclid - Geometry - 1892 - 460 pages
...line, standing on another straight line, makes the adjacent angles equal to one another, each of these angles is called a right angle, and the straight line...stands on the other is called a perpendicular to it. Therefore CH is a perpendicular drawn to the given straight line AB from the given point C without... ## Mathematics: Mechanic's bids and estimates. Mensuration for beginners. Easy ...

Seymour Eaton - 1899 - 362 pages
...standing on another straight line makes the adjacent angles equal to one another, I v/ \ GB each of these angles is called a right angle, and the straight line...stands on the other is called a perpendicular to it (Definitions). Therefore CH is a perpendicular drawn to the given straight line AB from the given point... ## Elementary Physiography: An Introduction to the Study of Nature

John Thornton - Physical geography - 1899 - 460 pages
...makes the adjaG. 9.— Pendulum swinging cent angles equal to one another, each through arc /«. r .1 and the straight line which stands on the other is called a perpendicular to it." Notice that " perpendicular " does not always mean upright, but making equal angles on both or all... 