Wie entstand die Formel für die Fläche eines Drachens?
Antworten:
Zerlege einen Drachen in zwei Dreiecke und nimm die Summe der Flächen der Dreiecke
Erläuterung:
Betrachten Sie das folgende Diagramm eines Drachens mit Diagonalen der Länge dd und ww:
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triangle ABD△ABD hat eine Fläche =("base" xx "height")/2=base×height2
color(white)("XXXXXXXXXXXXX")=(wx)/2XXXXXXXXXXXXX=wx2
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triangle BCD△BCD hat eine Fläche =("base" xx "height")/2=base×height2
color(white)("XXXXXXXXXXXXX")=(w xx (d-x))/2 = (wd)/2-(wx)/2XXXXXXXXXXXXX=w×(d−x)2=wd2−wx2
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"Area of kite"Area of kite
color(white)("XXX")=Area_"ABD" + Area_"BCD"XXX=AreaABD+AreaBCD
color(white)("XXX")= ((wx)/2) + ((wd)/2 - (wx)/2)XXX=(wx2)+(wd2−wx2)
color(white)("XXX")=(wd)/2XXX=wd2