Elements of Plane Geometry |
From inside the book
Results 1-5 of 29
Page 44
... bisect L ECA , and draw EH . CE = CA , ( Hyp . ) CH = CH , and La = Lb ; ( Cons . ) ΔCHE = Δ CHA , ( 83 ) and Now EH = AH . HB + EH > EB . Substitute AH and DE for their equals EH and EB . Then or AH + HB > DE , AB > DE . Q. E. D. ...
... bisect L ECA , and draw EH . CE = CA , ( Hyp . ) CH = CH , and La = Lb ; ( Cons . ) ΔCHE = Δ CHA , ( 83 ) and Now EH = AH . HB + EH > EB . Substitute AH and DE for their equals EH and EB . Then or AH + HB > DE , AB > DE . Q. E. D. ...
Page 48
... bisects the vertical angle and is perpendicular to the base . 96. COR . 2. - The straight line which bisects the vertical angle of an isosceles triangle bisects the base at right angles . 97. COR . 3. - Any equilateral triangle is ...
... bisects the vertical angle and is perpendicular to the base . 96. COR . 2. - The straight line which bisects the vertical angle of an isosceles triangle bisects the base at right angles . 97. COR . 3. - Any equilateral triangle is ...
Page 63
... d a B AB = CD , ( Hyp . ) BC = BC , La = Lb ; ( 62 ) AABC = ACDB , ( 83 ) Le = Ld ; AC and BD are || , ( 64 ) ABCD is a . ( 121 ) Q.E.D. THEOREM XLIV . 134. The diagonals of a parallelogram bisect ELEMENTS OF PLANE GEOMETRY . 63.
... d a B AB = CD , ( Hyp . ) BC = BC , La = Lb ; ( 62 ) AABC = ACDB , ( 83 ) Le = Ld ; AC and BD are || , ( 64 ) ABCD is a . ( 121 ) Q.E.D. THEOREM XLIV . 134. The diagonals of a parallelogram bisect ELEMENTS OF PLANE GEOMETRY . 63.
Page 64
... ( 128 ) Δ ΑΒΟ = A CDO ; ( 84 ) whence AO DO , and BO CO . 135. COR . - The diagonals of a rhombus bisect each other = Q. E. D. at right angles . THEOREM XLV . 136. The diagonals of a rectangle are 64 ELEMENTS OF PLANE GEOMETRY .
... ( 128 ) Δ ΑΒΟ = A CDO ; ( 84 ) whence AO DO , and BO CO . 135. COR . - The diagonals of a rhombus bisect each other = Q. E. D. at right angles . THEOREM XLV . 136. The diagonals of a rectangle are 64 ELEMENTS OF PLANE GEOMETRY .
Page 65
... : R △ CDB , = AD = BC . ( 122 ) ( 83 ) Q. E. D. 137. COR . - The diagonals of a square are equal and bisect each other at right angles . THEOREM XLVI . 138. If a parallel to the base 6 ELEMENTS OF PLANE GEOMETRY . 65.
... : R △ CDB , = AD = BC . ( 122 ) ( 83 ) Q. E. D. 137. COR . - The diagonals of a square are equal and bisect each other at right angles . THEOREM XLVI . 138. If a parallel to the base 6 ELEMENTS OF PLANE GEOMETRY . 65.
Other editions - View all
Common terms and phrases
AB² ABC and DEF AC and BC acute angle adjacent angles angles are equal angles equals angles formed arc AC BC² bisectors bisects centre CF meet chord common point Concave Polygon construct Convex Polygon COR.-The decagon DEF are similar diagonal BC diameter Draw the diagonal equally distant equals two right equiangular Equilateral Polygon exterior angles given circle given straight line homologous sides hypothenuse included angle intersect La=Lb Let ABCD line joining lines drawn measured by arc medial lines middle point oblique lines parallelogram perimeter PLANE GEOMETRY produced proportion Q. E. D. THEOREM Q. E. F. PROBLEM quadrilateral radii radius rectangle regular inscribed regular polygon respectively equal rhombus right angles right-angled triangle SCHOLIUM secant similar polygons square Subtract tangent third side trapezoid triangles are equal vertex vertical angle
Popular passages
Page 14 - Things which are equal to the same thing, are equal to each other. 2. If equals are added to equals, the sums are equal. 3. If equals are subtracted from equals, the remainders are equal. 4. If equals are added to unequals, the sums are unequal.
Page 83 - In a series of equal ratios, the sum of the antecedents is to the sum of the consequents as any antecedent is to its consequent.
Page 85 - CIRCLE is a plane figure bounded by a curved line, all the points of which are equally distant from a point within called the centre; as the figure ADB E.
Page 44 - If two triangles have two sides of the one respectively equal to two sides of the other, and the included angles unequal, the triangle which has the greater included angle has the greater third side.
Page 14 - Axioms. 1. Things which are equal to the same thing are equal to each other. 2. If equals are added to equals, the wholes are equal. 3. If equals are taken from equals, the remainders are equal.
Page 136 - In any triangle, the square of the side opposite an acute angle is equal to the sum of the squares of the other two sides, minus twice the product of one of these sides and the projection of the other side upon it.
Page 123 - Upon a given straight line to describe a segment of a circle, which shall contain an angle equal to a given rectilineal angle.
Page 55 - A polygon of three sides is a triangle ; of four, a quadrilateral; of five, a pentagon ; of six, a hexagon ; of seven, a heptagon; of eight, an octagon; of nine, a nonagon; of ten, a decagon; of twelve, a dodecagon.
Page 137 - In any triangle the square of the side opposite an acute angle is equal to the sum of the squares of the other two sides diminished by twice the product of one of those sides and the projection of the other upon that side.
Page 177 - From this proposition it is evident, that the square described on the difference of two lines is equivalent to the sum of the squares described on the lines respectively, minus twice the rectangle contained by the lines.