Books Books
From this it is manifest that if one angle of a triangle be equal to the other two it is a right angle, because the angle adjacent to it is equal to the same two ; (i.
The Elements of Euclid: In which the Propositions are Demonstrated in a New ... - Page 13
by Euclid - 1776 - 264 pages

## A Royal Road to Geometry: Or, an Easy and Familiar Introduction to the ...

Thomas Malton - 1774 - 482 pages
...conf.theAng.A + ABC + BCA(eq.FBA+ABC+CBG) are equal to two Right Angles. - - - C. 3. Th. i. CnR. i. Hence, if one Angle of a Triangle be equal to the other two Angles, it is a Right one. For, if either Side, containing the Right Angle, be produced \ the external...

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

Robert Simson - Trigonometry - 1775 - 520 pages
...of the left « fegment is faid to be lefs, than a right angle.' CoR. From this it is manifeft, that if one angle of a triangle be equal to the other two, it is a right angle, becaufe the angle adjacent to it is equal to the fame two ; and when the adjacent...

## The Elements of Euclid,: In which the Propositions are Demonstrated in a New ...

Euclid - Geometry - 1776 - 318 pages
...be a right one, each of the other angles will be half a right one. ^ 5. Any angle in an ^equilateral triangle is one third of two right angles, or two...produced, the adjacent angle is equal to the other two j therefore each of them are right angles. 7. All the inward angles of any right lined figure make...

## The Elements of Euclid: With Dissertations Intended to Assist and Encourage ...

Euclid, James Williamson - Euclid's Elements - 1781 - 324 pages
...wherefore the angle BAC is a right angle. Which was to be demonftrated. Cor From this it is manifeft that if one angle of a triangle be equal to the other two it is a right angle : for this reafon becaufe the adjacent angle is equal to the fame two : but (by...

## The First Six Books: Together with the Eleventh and Twelfth

Euclid - 1781 - 550 pages
...angle of thelcfa ' fegment is faid to be lefs, than a right angle.' CoR. From this it is manifeft, that if one angle of a triangle be equal to the other two, it is a right angle, becaufe the angle adjacent to it is equal to the fame two ; and when the ad jacent...

## The Elements of Euclid: Also the Book of Euclid's Data ...cor. viz. The ...

Robert Simson - Trigonometry - 1804
...angle of the lefs fegment is faid to be lefs * than a right angle.' CoR. From this it is manifeft, that if one angle of a triangle be equal to the other two, it is a right angle, becaufe the angle adjacent to it is equal to the fame two ; and when the adjacent...

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

John Playfair - Euclid's Elements - 1806 - 311 pages
...right angle. Therefore, in a circle, Book in. &c. QED COR. From the demonstration it is manifest that if one angle of a triangle be equal to the other two angles, it is a right angle. PROP. XXXII. THEOR. IF a straight line touch a circle, and from the point...

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

Euclides - 1816 - 528 pages
...of the less segment is said to be less, than a right ' angle.' COR. From this it is manifest, that if one angle of a triangle be equal to the other two, it is a right angle, because the angle adjacent to it is equal to the same two; and when the adjacent...