## Elements of Geometry |

### From inside the book

Results 1-5 of 17

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**angles**BAC ,**BAD**, are equal , each of these**angles**is called a right**angle**, and the line AB is said to be perpendicular to CD . 11. Every**angle**BAC ( fig . 4 ) , less than a right**angle**, is an acute**angle**; and every**angle**, DEF ... Page 10

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**angle BAD**= DAC , and that the angle BDA = ADC ; therefore these two last are right angles . Hence a straight line drawn from the vertex of an isosceles triangle , to the middle of the base , is perpendicular to the base , and divides ... Page 19

Adrien Marie Legendre. right angles , so that if a right angle be expressed by unity , the angle of an equilateral triangle will be expressed by . 78. Corollary vi . In every triangle ABC ( fig . 41 ) the exterior Fig . 41 ,

Adrien Marie Legendre. right angles , so that if a right angle be expressed by unity , the angle of an equilateral triangle will be expressed by . 78. Corollary vi . In every triangle ABC ( fig . 41 ) the exterior Fig . 41 ,

**angle BAD**is ... Page 32

... , that the arcs of a circle , which are used as a measure of angles , will also serve as the measure of different sectors of the same circle or of equal circles . THEOREM . 65 . 126. The inscribed

... , that the arcs of a circle , which are used as a measure of angles , will also serve as the measure of different sectors of the same circle or of equal circles . THEOREM . 65 . 126. The inscribed

**angle BAD**( 32 Elements of Geometry . Page 33

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**angle BAD**( fig . 64 ) ; we Fig . 64 . draw the diameter AE , and the radii CB , CD . The angle BCE , being the exterior angle of the triangle ABC , is equal to the sum of the two opposite interior angles , CAB , ABC . But , the ...### Other editions - View all

### Common terms and phrases

ABC fig adjacent angles altitude angle ACB angle BAD base ABCD bisect centre chord circ circular sector circumference circumscribed common cone consequently construction convex surface Corollary cube cylinder Demonstration diagonals diameter draw drawn equal and parallel equiangular equilateral equivalent faces figure four right angles frustum Geom gles greater hence homologous sides hypothenuse inclination inscribed circle isosceles join less let fall line AC manner mean proportional measure the half meet multiplied number of sides oblique lines opposite parallelogram parallelopiped perimeter perpendicular plane MN polyedron prism proposition pyramid S-ABC quadrilateral radii radius ratio rectangle regular polygon right angles right-angled triangle Scholium segment semicircumference side BC similar solid angle sphere spherical polygons spherical triangle square described straight line tangent THEOREM three plane angles triangle ABC triangular prism triangular pyramids vertex vertices whence