Question and Answers Forum

All Questions      Topic List

Mensuration Questions

Previous in All Question      Next in All Question      

Previous in Mensuration      Next in Mensuration      

Question Number 193149 by Mingma last updated on 04/Jun/23

Answered by ajfour last updated on 05/Jun/23

((√3)/4)p^2 =A  p=k(√A)    where   k^2 =(4/( (√3)))  q=k(√B)  B=9A  P((p/2),((p(√3))/2))  Q(((2p+q)/2), ((q(√3))/2))  q=3p      PQ=(√((((p+q)/2))^2 +3(((q−p)/2))^2 ))  PQ=c=(√7)p  m=(((q−p)(√3))/(q+p))=((√3)/2)  M(((3p+q)/4),(((p+q)(√3))/4))  M(((3p)/2), (√3)p)  ((c(√3))/2)=((√(21))/2)p  tan φ=(1/m)=(2/( (√3)))  ⇒  sin φ=(2/( (√7)))  H=y_M +((c(√3))/2)sin φ      =(√3)p+((p(√7)(√3))/2)×(2/( (√7)))     =2(√3)p  p=k  as  A=1  H=2(√3)k  W=p+q=4p=4k  Rectangle area=WH     =(4k)(2(√3)k)=8(√3)k^2      =8(√3)×(4/( (√3)))= 32  sq. units.

$$\frac{\sqrt{\mathrm{3}}}{\mathrm{4}}{p}^{\mathrm{2}} ={A} \\ $$$${p}={k}\sqrt{{A}}\:\:\:\:{where}\:\:\:{k}^{\mathrm{2}} =\frac{\mathrm{4}}{\:\sqrt{\mathrm{3}}} \\ $$$${q}={k}\sqrt{{B}} \\ $$$${B}=\mathrm{9}{A} \\ $$$${P}\left(\frac{{p}}{\mathrm{2}},\frac{{p}\sqrt{\mathrm{3}}}{\mathrm{2}}\right) \\ $$$${Q}\left(\frac{\mathrm{2}{p}+{q}}{\mathrm{2}},\:\frac{{q}\sqrt{\mathrm{3}}}{\mathrm{2}}\right) \\ $$$${q}=\mathrm{3}{p}\:\:\:\: \\ $$$${PQ}=\sqrt{\left(\frac{{p}+{q}}{\mathrm{2}}\right)^{\mathrm{2}} +\mathrm{3}\left(\frac{{q}−{p}}{\mathrm{2}}\right)^{\mathrm{2}} } \\ $$$${PQ}={c}=\sqrt{\mathrm{7}}{p} \\ $$$${m}=\frac{\left({q}−{p}\right)\sqrt{\mathrm{3}}}{{q}+{p}}=\frac{\sqrt{\mathrm{3}}}{\mathrm{2}} \\ $$$${M}\left(\frac{\mathrm{3}{p}+{q}}{\mathrm{4}},\frac{\left({p}+{q}\right)\sqrt{\mathrm{3}}}{\mathrm{4}}\right) \\ $$$${M}\left(\frac{\mathrm{3}{p}}{\mathrm{2}},\:\sqrt{\mathrm{3}}{p}\right) \\ $$$$\frac{{c}\sqrt{\mathrm{3}}}{\mathrm{2}}=\frac{\sqrt{\mathrm{21}}}{\mathrm{2}}{p} \\ $$$$\mathrm{tan}\:\phi=\frac{\mathrm{1}}{{m}}=\frac{\mathrm{2}}{\:\sqrt{\mathrm{3}}}\:\:\Rightarrow\:\:\mathrm{sin}\:\phi=\frac{\mathrm{2}}{\:\sqrt{\mathrm{7}}} \\ $$$${H}={y}_{{M}} +\frac{{c}\sqrt{\mathrm{3}}}{\mathrm{2}}\mathrm{sin}\:\phi \\ $$$$\:\:\:\:=\sqrt{\mathrm{3}}{p}+\frac{{p}\sqrt{\mathrm{7}}\sqrt{\mathrm{3}}}{\mathrm{2}}×\frac{\mathrm{2}}{\:\sqrt{\mathrm{7}}} \\ $$$$\:\:\:=\mathrm{2}\sqrt{\mathrm{3}}{p} \\ $$$${p}={k}\:\:{as}\:\:{A}=\mathrm{1} \\ $$$${H}=\mathrm{2}\sqrt{\mathrm{3}}{k} \\ $$$${W}={p}+{q}=\mathrm{4}{p}=\mathrm{4}{k} \\ $$$${Rectangle}\:{area}={WH} \\ $$$$\:\:\:=\left(\mathrm{4}{k}\right)\left(\mathrm{2}\sqrt{\mathrm{3}}{k}\right)=\mathrm{8}\sqrt{\mathrm{3}}{k}^{\mathrm{2}} \\ $$$$\:\:\:=\mathrm{8}\sqrt{\mathrm{3}}×\frac{\mathrm{4}}{\:\sqrt{\mathrm{3}}}=\:\mathrm{32}\:\:{sq}.\:{units}. \\ $$

Commented by Mingma last updated on 05/Jun/23

Perfect �� I'm excited you corrected yourself!

Terms of Service

Privacy Policy

Contact: info@tinkutara.com