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

## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

John Playfair - Euclid's Elements - 1806 - 320 pages
...angle at a point, it may be expressed ' by a letter placed at that point ; as the angle at E.' VII. When a straight line standing on another straight...stands on the other is called a perpendicular to it. _____ VIII, Book I. An obtuse angle is that which is greater than a right angle. IX. An acute angle...

## The Elements of Euclid: The Errors, by which Theon, Or Others, Have Long Ago ...

Robert Simson - Trigonometry - 1806 - 518 pages
...placed at that point; as < the angle at E.' X. When a straight line standing on another straight lii>e makes the adjacent angles equal to one another, each...stands on the other is called a perpendicular to it. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle is that which...

## Pantologia. A new (cabinet) cyclopædia, by J.M. Good, O. Gregory ..., Volume 5

John Mason Good - 1813 - 722 pages
...of two straight lines to or.e another, which meet together, but are not in the same straight line. 10. When a straight line standing on another straight...stands on the other is called a perpendicular to it. 11. An obtuse an¿le is that which is greater 'than a right angle. IS. An acnte angle is that which...

## The Elements of Euclid; viz. the first six books, together with the eleventh ...

Euclides - 1814 - 558 pages
...one angle at a point, it may be ex' pressed by a letter placed at that point; as the angle at E.' X. When a straight line standing on another straight...stands on the other is called a perpendicular to it. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle is that which...

## Elements of Geometry: Containing the First Six Books of Euclid: With a ...

John Playfair - 1819 - 317 pages
...one angle at a point, it may be expressed by a letter placed at that point ; as the angle at E.' VII. When a straight line standing on another straight...stands on the other is called a perpendicular to it. VIII. An obtuse angle is that which is greater than a right angle. An acute angle is that which is...

## Pantologia. A new (cabinet) cyclopædia, by J.M. Good, O. Gregory ..., Volume 5

John Mason Good - 1819 - 740 pages
...adjacent angles equal to one another, each of (lie angles is called и right angle; and the ira glu line which stands on the other is called a perpendicular to it. 11. An obtuse angle is that which is g cater than a right an^le. 12. Ли acute angle is that which...

## The Elements of Euclid: Viz. the First Six Books, Together with the Eleventh ...

Euclid, Robert Simson - Geometry - 1821 - 514 pages
...angle at ' a point, it may be expressed by the letter placed at that point; ' as the angle at E.' X. When a straight line standing on another straight...which stands on the other is called a perpendicular to „« —__ it. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle...

## A Popular Course of Pure and Mixed Mathematics ...: With Tables of ...

Peter Nicholson - Mathematics - 1825 - 372 pages
...only one angle at a point, it may be expressed by a letter placed at that point ; as the angle at E.' 10. When a straight line standing on another straight...stands on the other is called a perpendicular to it. 11. An obtuse angle is that which is greater than a right angle. ^ 12. An acute angle is that which...