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MATH / Five points A, B, C, D, and O lie on a flat field. A is directly north of O, B is directly west of O, C is directly south of O, and D is directly east of O. The distance between C …

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Answer published by the source. Consult the official source to check your work against its answer.

problem

Five points AA, BB, CC, DD, and OO lie on a flat field. AA is directly north of OO, BB is directly west of OO, CC is directly south of OO, and DD is directly east of OO. The distance between CC and DD is 140 m. A hot-air balloon is positioned in the air at HH directly above OO. The balloon is held in place by four ropes HAHA, HBHB, HCHC, and HDHD. Rope HCHC has length 150 m and rope HDHD has length 130 m. [asy] size(250); pair A, B, C, D, O, H, W, X, Y, Z; O=(0,0); A=(1,1); D=(1.5,-.3); B=(-1.5,.3); C=(-1,-1); H=(0,2.5); W=(5/3)*(A+D); X=(5/3)*(A+B); Y=(-1)*(W); Z=(-1)*(X); draw(W--X--Y--Z--W); draw(A--C); draw(B--D); draw(O--H, linewidth(1)); draw(A--H, dashed); draw(B--H, dashed); draw(C--H, dashed); draw(D--H, dashed); dot(A); dot(B); dot(C); dot(D); dot(O); dot(H); label("A", A, NE); label("B", B, SW); label("C", C, SE); label("D", D, NE); label("O", O, SE); label("H", H, NW); [/asy] To reduce the total length of rope used, rope HCHC and rope HDHD are to be replaced by a single rope HPHP where PP is a point on the straight line between CC and DD. (The balloon remains at the same position HH above OO as described above.) Determine the greatest length of rope that can be saved.
Plain-text mathematical notation (without MathML)
Five points A, B, C, D, and O lie on a flat field.  A is directly north of O, B is directly west of O, C is directly south of O, and D is directly east of O. The  distance between C and D is 140 m.  A hot-air balloon is positioned in the air at H directly above O. The balloon is held in place by four ropes HA, HB, HC, and HD.  Rope HC has length 150 m and rope HD has length 130 m. [asy]
size(250);
pair A, B, C, D, O, H, W, X, Y, Z;
O=(0,0);
A=(1,1);
D=(1.5,-.3);
B=(-1.5,.3);
C=(-1,-1);
H=(0,2.5);
W=(5/3)*(A+D);
X=(5/3)*(A+B);
Y=(-1)*(W);
Z=(-1)*(X);
draw(W--X--Y--Z--W);
draw(A--C);
draw(B--D);
draw(O--H, linewidth(1));
draw(A--H, dashed);
draw(B--H, dashed);
draw(C--H, dashed);
draw(D--H, dashed);
dot(A);
dot(B);
dot(C);
dot(D);
dot(O);
dot(H);
label("A", A, NE);
label("B", B, SW);
label("C", C, SE);
label("D", D, NE);
label("O", O, SE);
label("H", H, NW);
[/asy]

To reduce the total length of rope used, rope HC and rope HD are to be replaced by a single rope HP where P is a point on the straight line between C and D. (The balloon remains at the same position H above O as described above.)  Determine the greatest length of rope that can be saved.
Original LaTeX notation
Five points $A$, $B$, $C$, $D$, and $O$ lie on a flat field.  $A$ is directly north of $O$, $B$ is directly west of $O$, $C$ is directly south of $O$, and $D$ is directly east of $O$. The  distance between $C$ and $D$ is 140 m.  A hot-air balloon is positioned in the air at $H$ directly above $O$. The balloon is held in place by four ropes $HA$, $HB$, $HC$, and $HD$.  Rope $HC$ has length 150 m and rope $HD$ has length 130 m. [asy]
size(250);
pair A, B, C, D, O, H, W, X, Y, Z;
O=(0,0);
A=(1,1);
D=(1.5,-.3);
B=(-1.5,.3);
C=(-1,-1);
H=(0,2.5);
W=(5/3)*(A+D);
X=(5/3)*(A+B);
Y=(-1)*(W);
Z=(-1)*(X);
draw(W--X--Y--Z--W);
draw(A--C);
draw(B--D);
draw(O--H, linewidth(1));
draw(A--H, dashed);
draw(B--H, dashed);
draw(C--H, dashed);
draw(D--H, dashed);
dot(A);
dot(B);
dot(C);
dot(D);
dot(O);
dot(H);
label("A", A, NE);
label("B", B, SW);
label("C", C, SE);
label("D", D, NE);
label("O", O, SE);
label("H", H, NW);
[/asy]

To reduce the total length of rope used, rope $HC$ and rope $HD$ are to be replaced by a single rope $HP$ where $P$ is a point on the straight line between $C$ and $D$. (The balloon remains at the same position $H$ above $O$ as described above.)  Determine the greatest length of rope that can be saved.

level

Level 5

type

Geometry

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Official source

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