## Elements of Geometry |

### From inside the book

Results 1-5 of 68

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**triangle**is that which has one right angle . The side opposite to the right angle is called the hypothenuse . Fig . 10. Thus**ABC**( fig . 10 ) is a**triangle**right - angled at A , and the side BC is the hypothenuse . Fig . 11 . Fig . 12 ... Page 7

... triangle DEF is equal to the

... triangle DEF is equal to the

**triangle ABC**( 26 ) . 37. Corollary . When , in two triangles , these three things are equal , namely , the angle A = D , the side AB DE , and the side AC = DF , we may thence infer , that the other three ... Page 8

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**triangle ABC**, there be drawn straight lines OB , OC , to the extremities of BC , one of its sides , the sum of these lines will be less than that of AB , AC , the two other sides . Demonstration . Let BO be produced till it meet the ... Page 10

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**triangle**, to the middle of the base , is perpendicular to the base , and divides the ver- tical angle into two ...**ABC**= ACB ( fig . 29 ) , the side AC will be equal to the side AB . For , if these sides are not equal , let AB be the ... Page 11

... triangle CBF is equal to the

... triangle CBF is equal to the

**triangle ABC**. For the angle CBF is a right angle ( 29 ) , as well as CBA , and the side BF = BA ; therefore the triangles are equal ( 36 ) , and the angle BCF BCA . But BCA is , by hypothesis , a right ...### 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