Question Number 226143 by ajfour last updated on 20/Nov/25

Commented by fantastic2 last updated on 22/Nov/25

$${Tony}:\:{yes}\:\:{to}\:{all}\:{statements} \\ $$
Commented by TonyCWX last updated on 22/Nov/25

$${Let}\:{me}\:{ask}\:{a}\:{few}\:{questions}\:{first}\:{before}\:{I}\:{attempt}\:{this}. \\ $$$$\mathrm{1}.\:{Is}\:{straight}\:{line}\:{SP}\:{and}\:{RQ}\:{parallel}\:{to}\:{each}\:{other}? \\ $$$$\mathrm{2}.\:{Is}\:{straight}\:{line}\:{SR}\:{and}\:{PQ}\:{parallel}\:{to}\:{each}\:{other}? \\ $$$$\mathrm{3}.\:{Is}\:{straight}\:{line}\:{SP}\:{and}\:{PQ}\:{perpendicular}\:{to}\:{each}\:{other}? \\ $$
Commented by TonyCWX last updated on 22/Nov/25

Commented by TonyCWX last updated on 22/Nov/25

$${For}\:{a}=\mathrm{10},\:{b}=\mathrm{6},\:{k}=\frac{\mathrm{1}}{\mathrm{2}} \\ $$$${GE}=\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{6}\right)=\mathrm{3}\:{and}\:{EF}=\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{10}\right)=\mathrm{5} \\ $$$${As}\:{you}\:{can}\:{see},\:{they}\:{are}\:{not}\:{necessarily}\:{parallel}\:{to}\:{each}\:{other}. \\ $$$${The}\:{value}\:{of}\:{angle}\:{may}\:{change}\:{with}\:{the}\:{position}\:{of}\:{point}\:{E}. \\ $$
Commented by fantastic2 last updated on 22/Nov/25

$${see}\:{your}\:{picture}\:{and}\:{your} \\ $$$${previous}\:{statements}\:\mathrm{123} \\ $$
Commented by TonyCWX last updated on 22/Nov/25

$${Are}\:{there}\:{any}\:{differences}? \\ $$$${If}\:{so},\:{please}\:{point}\:{them}\:{out}. \\ $$
Commented by fantastic2 last updated on 22/Nov/25
CG should be perpendicular to de otherwise they can't be parallel CG and EF can't be parallel
Commented by TonyCWX last updated on 22/Nov/25

$${But}\:{as}\:{you}\:{can}\:{see}. \\ $$$${The}\:{properties}\:{still}\:{hold}. \\ $$
Commented by fantastic2 last updated on 22/Nov/25

$${PQRS}\:{is}\:{a}\:{Rectangle} \\ $$
Commented by TonyCWX last updated on 22/Nov/25

$${I}'{ll}\:{just}\:{wait}\:{until}\:{Sir}\:{Ajfour}\:{comment}. \\ $$
Commented by fantastic2 last updated on 22/Nov/25

$${ok}\:{that}\:{looks}\:{like}\:{a}\:{fair}\:{option} \\ $$
Commented by mr W last updated on 22/Nov/25

$${i}\:{guess}\:{ajfour}\:{sir}\:{has}\:{meant}\:{that} \\ $$$${both}\:{ABCD}\:{and}\:{SPQR}\:{are} \\ $$$${rectangle}.\:{otherwise}\:{there}\:{is}\:{no} \\ $$$${unique}\:{solution}. \\ $$
Commented by fantastic2 last updated on 22/Nov/25

$${i}\:{also}\:{think}\:{that}.{But}\:{lets}\:{see} \\ $$$${what}\:{ajfour}\:{sir}\:{says} \\ $$
Answered by fantastic2 last updated on 20/Nov/25

$${i}\:{get}\:\theta=\mathrm{cos}^{−\mathrm{1}} \left(\frac{{b}}{{a}}\right) \\ $$
Answered by fantastic2 last updated on 20/Nov/25

Commented by fantastic2 last updated on 20/Nov/25

$${b}\mathrm{tan}\:\theta+{ka}\mathrm{cos}\:\theta={a} \\ $$$$\Rightarrow{k}=\frac{{a}−{b}\mathrm{tan}\:\theta}{{a}\mathrm{cos}\:\theta} \\ $$$${ka}+{kb}\mathrm{tan}\:\theta={a}\mathrm{cos}\:\theta \\ $$$$\Rightarrow{k}=\frac{{a}\mathrm{cos}\:\theta}{{a}+{b}\mathrm{tan}\:\theta} \\ $$$${so} \\ $$$$\frac{{a}−{b}\mathrm{tan}\:\theta}{{a}\mathrm{cos}\:\theta}=\frac{{a}\mathrm{cos}\:\theta}{{a}+{b}\mathrm{tan}\:\theta} \\ $$$${a}^{\mathrm{2}} \mathrm{cos}\:^{\mathrm{2}} \theta={a}^{\mathrm{2}} −{b}^{\mathrm{2}} \mathrm{tan}\:^{\mathrm{2}} \theta \\ $$$$\Rightarrow{a}^{\mathrm{2}} \mathrm{sin}\:^{\mathrm{2}} \theta={b}^{\mathrm{2}} \mathrm{tan}\:^{\mathrm{2}} \theta \\ $$$$\Rightarrow\mathrm{cos}\:\theta=\frac{{b}}{{a}} \\ $$
Commented by fantastic2 last updated on 22/Nov/25

Commented by fantastic2 last updated on 22/Nov/25

$${what}\:{i}\:{get} \\ $$$$\frac{{kb}}{\mathrm{cos}\:\theta}+{ka}\mathrm{sin}\:\theta={b} \\ $$$$\Rightarrow{k}=\frac{{b}\mathrm{cos}\:\theta}{{b}+{a}\mathrm{cos}\:\theta\mathrm{sin}\:\theta} \\ $$$${b}\mathrm{tan}\:\theta+{ka}\mathrm{cos}\:\theta={a} \\ $$$$\Rightarrow{k}=\frac{{a}−{b}\mathrm{tan}\:\theta}{{a}\mathrm{cos}\:\theta} \\ $$$${kb}+{a}\mathrm{sin}\:\theta=\frac{{b}}{\mathrm{sin}\:\theta} \\ $$$$\Rightarrow{k}=\frac{{b}−{a}\mathrm{sin}\:^{\mathrm{2}} \theta}{{b}\mathrm{sin}\:\theta} \\ $$$${kb}\mathrm{tan}\:\theta+{ka}={a}\mathrm{cos}\:\theta \\ $$$$\Rightarrow{k}=\frac{{a}\mathrm{cos}\:\theta}{{a}+{b}\mathrm{tan}\:\theta} \\ $$
Commented by fantastic2 last updated on 22/Nov/25

$${i}\:{was}\:{right} \\ $$