In the diagram below, $\angle PQR = \angle PRQ = \angle STR = \angle TSR$, $RQ = 8$, and $SQ = 2$. Find $PQ$.
[asy]
pair A,B,C,D,E;
A = (0, 0.9);
B = (-0.4, 0);
C = (0.4, 0);
D = (-0.275, 0.16);
E = (0.11, 0.65);
draw(A--B);
draw(A--C);
draw(B--C);
draw(B--E);
draw(C--D);
label("$P$",A,N);
label("$Q$", B, S);
label("$R$", C, S);
label("$S$", D, S);
label("$T$", E, W);
[/asy]
In the diagram below,
∠PQR=∠PRQ=∠STR=∠TSR=∠A,RQ=8, and SQ=2.
Find PQ.
Let ∠QPR=180∘−2ALet ∠RQT=180∘−2ALet ∠TRS=180∘−2ALet ∠PTQ=180∘−ALet PQ=x Let QR=QT=8 Let TR=SR=y
ST=QT−SQST=8−2ST=6
In △[QPT]:sin(180∘−2A)8=sin(180∘−A)xsin(2A)8=sin(A)xsin(2A)sin(A)=8x(1)In △[QTR]:sin(180∘−2A)y=sin(A)8sin(2A)y=sin(A)8sin(2A)sin(A)=y8(2)In △[QSR]:sin(180∘−2A)6=sin(A)ysin(2A)6=sin(A)ysin(2A)sin(A)=6y(3)
(2)=(3):y8=6yy2=48y2=16∗3y=4√3(2)=(1):y8=8xxy=64x=64yx=644√3x=16√3x=16√3∗√3√3x=163√3
PQ=163√3
Nice work, heureka, as always!!!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
QS = TU = 2
QT = QR = 8
QW = 5
RV = 4
TW = sqrt(QT2 - QW2)
RT = sqrt(TW2 + RW2)
RW / RT = RV / PR
PQ = PR = (RT * RV) / RW