Question and Answers Forum

All Questions      Topic List

Geometry Questions

Previous in All Question      Next in All Question      

Previous in Geometry      Next in Geometry      

Question Number 14797 by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

Commented by mrW1 last updated on 05/Jun/17

we know when the top point of a  triangle is moved parallel to the base  line, the area of the triangle remains  unchanged.  we move the point E in this way such  that it lies on the line BD.   let M=intersection point of AC and BD.  A_(ΔACE) =(1/2)×AC×MB  =(1/2)×DB×(((BD)/2)−BE)  =(1/2)×(DE+BE)×(((DE+BE)/2)−BE)  =(1/2)×(10+4)×(((10+4)/2)−4)  =21    in general, with p=DE and q=BE  A_(ΔAEC) =(((p+q)(p−q))/4)

weknowwhenthetoppointofatriangleismovedparalleltothebaseline,theareaofthetriangleremainsunchanged.wemovethepointEinthiswaysuchthatitliesonthelineBD.letM=intersectionpointofACandBD.AΔACE=12×AC×MB=12×DB×(BD2BE)=12×(DE+BE)×(DE+BE2BE)=12×(10+4)×(10+424)=21ingeneral,withp=DEandq=BEAΔAEC=(p+q)(pq)4

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

ABCD ,square.DE=10,EB=4.  .............(√(.............))..........(√(..............))  S_(AEC) =?

ABCD,square.DE=10,EB=4...................................................SAEC=?

Commented by RasheedSoomro last updated on 04/Jun/17

AB=?

AB=?

Commented by ajfour last updated on 04/Jun/17

Commented by ajfour last updated on 04/Jun/17

C at the top corner, A at the   bottom. Origin of coordinates  is center of square., axes along  diagonals of square.  Further let side of square=a(√2)  Equation of circles:   (x+a)^2 +y^2 =100   (x−a)^2 +y^2 =16  subtracting we get x coordinate  of points of intersection:    4ax = 84    ⇒  ax=21  S_(△AEC) = (1/2)(2a)x= ax =21 .

Catthetopcorner,Aatthebottom.Originofcoordinatesiscenterofsquare.,axesalongdiagonalsofsquare.Furtherletsideofsquare=a2Equationofcircles:(x+a)2+y2=100(xa)2+y2=16subtractingwegetxcoordinateofpointsofintersection:4ax=84ax=21SAEC=12(2a)x=ax=21.

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

hello mr Ajfour.  i think equations of circles should  be as below:  (x+((a(√2))/2))^2 +y^2 =100  (x−((a(√2))/2))^2 +y^2 =16  .

hellomrAjfour.ithinkequationsofcirclesshouldbeasbelow:(x+a22)2+y2=100(xa22)2+y2=16.

Commented by ajfour last updated on 04/Jun/17

yes, in solving i assumed  diagonal of square as 2a.   answer should be 21 still..

yes,insolvingiassumeddiagonalofsquareas2a.answershouldbe21still..

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

when you assume square side=a  then diagonal length=a(√2). (not:  2a)

whenyouassumesquareside=athendiagonallength=a2.(not:2a)

Commented by ajfour last updated on 04/Jun/17

thanks, but just now i edited,  side of square as a(√2) , diagonal  length is of course 2a then.

thanks,butjustnowiedited,sideofsquareasa2,diagonallengthisofcourse2athen.

Commented by mrW1 last updated on 05/Jun/17

A_(AEC) =(1/2)×14×(((14)/2)−4)=7×3=21

AAEC=12×14×(1424)=7×3=21

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 05/Jun/17

so beautiful and nice!   dear mrW1.please show us: how?

sobeautifulandnice!dearmrW1.pleaseshowus:how?

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 05/Jun/17

nice and beautiful.thank a lot my master.

niceandbeautiful.thankalotmymaster.

Answered by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

Commented by b.e.h.i.8.3.4.1.7@gmail.com last updated on 04/Jun/17

square sides=a

squaresides=a

Terms of Service

Privacy Policy

Contact: info@tinkutara.com