proportioned angles

  • Required accessories - pencil, compass, unmarked straightedge



    Odd proportion angles (there is a proportion of the steam angles) of the element 3 (which may be 5,7,9, ...) and the base angle [TEX] 45 ^ o[/TEX] (which can be any angle which is obtainable by means of compass and straightedge)


    The angle CAB [TEX]45 ^ o[/TEX] can be obtained with a compass and unmarked ruler, he added angles (each have [TEX]45 ^ o[/TEX]) DAC and EAD, obtained angle EAB [TEX]135 ^ o[/TEX]is the starting angle


    Merge points E (D, C, B) and get a longer ED (DC, CB)


    Along the DC from the point C draw is normal that intersects the segment AB, the intersection is a point G


    Divider AG and from point G draw a circular arc to a longer EA and H get the point, and the arc GH, join the dots G and H and get along GH


    Longer GH (ED, DC, CB) are equal, the arc EB's first circular arc can be made smaller or larger with a constant radius AB, arc GH is the second circular arc can be made smaller or larger with a constant radius AG


    INCREASING THE ANGLE
    the starting angle EAB add angle FAE [TEX]15 ^ o[/TEX] get the angle FAB [TEX]150 ^ o[/TEX] - continued in the next post

  • - previous post was in error -

    Required accessories - pencil, compass, unmarked straightedge

    basic angle - can be any angle that can be construction using compass and unmarked straightedge, angle CAB [TEX] 45 ^ o[/TEX]

    starting angle - sum of 2, 3, 4, 5, ... basic angles , EAB [TEX] 135 ^ o[/TEX]
    sum angles CAB [TEX] 45 ^ o[/TEX] DAC [TEX] 45 ^ o[/TEX] EAD [TEX] 45 ^ o[/TEX]

    difference angle - the angle which increases or decreases the starting angle. difference starting angle and the angle of whom do not know the measure , this angle is known to see a procedure HAB [TEX] 30 ^ o[/TEX]

    straightedge AB is divided into three parts AF , how we have a basis in the angles starting angle

    divider AF from point A the circular arc FG

    section straightedge AH the circular arc FG , point I

    straightedges FG , ED
    --------------------------------------
    will continue - if there are errors

  • basic angle CAB [tex]45^o[/tex]

    starting angle EAB [tex]135^o[/tex] consists of the sum of the angles CAB [tex]45^o[/tex] DAC [tex]45^o [/tex]EAD [tex]45^o[/tex]

    DC straightedge the normal to the point D , gets the point F

    AF divider from point A, we get the point G

    divider AB from point F, divider AB from point G, we get the point H

    HG divider from point H, creates a circular arc FG

    difference angle IAB [tex]30^o[/tex]

    section IA and longer circular arc FG is a point J

  • applies this photo

    bisection angle DAC is obtained by point J
    along AJ
    GF section circular arc and along the AJ, obtained point L
    AF divider, from the point J, we get the point O
    divider AF, from point A circle c1
    divider GL, from the point J, the circuit d1, get the points P and Q