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 75296 by ajfour last updated on 09/Dec/19

Commented by ajfour last updated on 09/Dec/19

If perimeter of △PQR is p, find  maximum area of △PQR in  terms of a,b,c,p.   (p<a+b+c)

IfperimeterofPQRisp,findmaximumareaofPQRintermsofa,b,c,p.(p<a+b+c)

Commented by mr W last updated on 09/Dec/19

p_(min) =((a^2 (b^2 +c^2 −a^2 )+b^2 (c^2 +a^2 −b^2 )+c^2 (a^2 +b^2 −c^2 ))/(2abc))  p_(mac) =a+b+c  p_(min) <p<p_(max)

pmin=a2(b2+c2a2)+b2(c2+a2b2)+c2(a2+b2c2)2abcpmac=a+b+cpmin<p<pmax

Answered by mr W last updated on 10/Dec/19

Commented by mr W last updated on 10/Dec/19

p=(√((1−β)^2 b^2 +γ^2 c^2 −2(1−β)γbc cos A))        +(√((1−γ)^2 c^2 +α^2 a^2 −2(1−γ)αca cos B))        +(√((1−α)^2 a^2 +β^2 b^2 −2(1−α)βab cos C))  A_(ΔPQR) =A_(ΔABC) −(1/2)(1−β)γbc sin A                           −(1/2)(1−γ)αca sin B                           −(1/2)(1−α)βab sin C  A_(ΔPQR) =A_(ΔABC) −(1/2)A  A=(1−β)γbc sin A+(1−γ)αca sin B+(1−α)βab sin C  ...

p=(1β)2b2+γ2c22(1β)γbccosA+(1γ)2c2+α2a22(1γ)αcacosB+(1α)2a2+β2b22(1α)βabcosCAΔPQR=AΔABC12(1β)γbcsinA12(1γ)αcasinB12(1α)βabsinCAΔPQR=AΔABC12AA=(1β)γbcsinA+(1γ)αcasinB+(1α)βabsinC...

Terms of Service

Privacy Policy

Contact: info@tinkutara.com