IfΔABC&ΔDEFaresimilarthen
ABDE=ACDF=BCEF.
Wecanobtaintheabovelengthsbythedistanceformula
d=√(x2−x1)2+(y2−y1)2
andinvestigateiftheratiosareequal.
Statement−
ΔABC&ΔDEFaresimilarsinceallthe3sidesofthetrianglesareinproportion.
Justification−
LetusobtainthelengthsofthesidesofΔABC&ΔDEF
bythedistanceformulad=√(x2−x1)2+(y2−y1)2.
InΔABCtheverticesareA(2,0),B(−2,0),C(0,2).
∴AB=√(−2−2)2+(0)2=4units.
SimilarlyBC=√(0+2)2+(2−0)2=2√2units
andAC=√(0−2)2+(2−0)2=2√2units.
AgaininΔDEFtheverticesareA(4,0),B(−4,0),C(0,4).
∴DE=√(−4−4)2+(0)2=8units.
SimilarlyEF=√(0+4)2+(4−0)2=4√2units
andDF=√(0−4)2+(4−0)2=4√2units.
SoABDE=48=12.
ACDF=2√24√2=12and
BCEF=2√24√2=12
SoABDE=ACDF=BCEF.
∴Thegivenstatementistrue
.Ans−TRUE.