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MATH / Circles with centers at O and P have radii 2 and 4, respectively, and are externally tangent. Points A and B on the circle with center O and points C and D on the circle with cente…
Problem
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problem
Circles with centers at and have radii 2 and 4, respectively, and are externally tangent. Points and on the circle with center and points and on the circle with center are such that and are common external tangents to the circles. What is the area of the concave hexagon ?
[asy]
pair A,B,C,D,H,O,P;
O = (0,0);
P = (6,0);
H = (-6,0);
A = intersectionpoint(arc((A + H)/2, abs(A - H)/2, 0, 180), arc(O, 2, 0, 180));
D = intersectionpoint(arc((A + P)/2, abs(A - P)/2, 0, 180), arc(P, 4, 0, 180));
B = reflect(O,P)*(A);
C = reflect(O,P)*(D);
draw(O--P,linewidth(0.7));
draw(Circle(O,2),linewidth(0.7));
draw(Circle(P,4),linewidth(0.7));
draw(interp(A,D,-0.2)--interp(A,D,1.2),linewidth(0.7));
draw(interp(B,C,-0.2)--interp(B,C,1.2),linewidth(0.7));
draw(A--O--B,linewidth(0.7));
draw(D--P--C,linewidth(0.7));
label("",O,SE);
label("",P,E);
label("",D,NW);
label("",A,NW);
label("",B,S);
label("",C,S);
label("2",(-0.45,0.95),E);
label("6",(3,0),N);
label("4",(5.55,1.95),E);
[/asy]
Plain-text mathematical notation (without MathML)
Circles with centers at O and P have radii 2 and 4, respectively, and are externally tangent. Points A and B on the circle with center O and points C and D on the circle with center P are such that (AD)¯ and (BC)¯ are common external tangents to the circles. What is the area of the concave hexagon AOBCPD?
[asy]
pair A,B,C,D,H,O,P;
O = (0,0);
P = (6,0);
H = (-6,0);
A = intersectionpoint(arc((A + H)/2, abs(A - H)/2, 0, 180), arc(O, 2, 0, 180));
D = intersectionpoint(arc((A + P)/2, abs(A - P)/2, 0, 180), arc(P, 4, 0, 180));
B = reflect(O,P)*(A);
C = reflect(O,P)*(D);
draw(O--P,linewidth(0.7));
draw(Circle(O,2),linewidth(0.7));
draw(Circle(P,4),linewidth(0.7));
draw(interp(A,D,-0.2)--interp(A,D,1.2),linewidth(0.7));
draw(interp(B,C,-0.2)--interp(B,C,1.2),linewidth(0.7));
draw(A--O--B,linewidth(0.7));
draw(D--P--C,linewidth(0.7));
label("O",O,SE);
label("P",P,E);
label("D",D,NW);
label("A",A,NW);
label("B",B,S);
label("C",C,S);
label("2",(-0.45,0.95),E);
label("6",(3,0),N);
label("4",(5.55,1.95),E);
[/asy]Original LaTeX notation
Circles with centers at $O$ and $P$ have radii 2 and 4, respectively, and are externally tangent. Points $A$ and $B$ on the circle with center $O$ and points $C$ and $D$ on the circle with center $P$ are such that $\overline{AD}$ and $\overline{BC}$ are common external tangents to the circles. What is the area of the concave hexagon $AOBCPD$?
[asy]
pair A,B,C,D,H,O,P;
O = (0,0);
P = (6,0);
H = (-6,0);
A = intersectionpoint(arc((A + H)/2, abs(A - H)/2, 0, 180), arc(O, 2, 0, 180));
D = intersectionpoint(arc((A + P)/2, abs(A - P)/2, 0, 180), arc(P, 4, 0, 180));
B = reflect(O,P)*(A);
C = reflect(O,P)*(D);
draw(O--P,linewidth(0.7));
draw(Circle(O,2),linewidth(0.7));
draw(Circle(P,4),linewidth(0.7));
draw(interp(A,D,-0.2)--interp(A,D,1.2),linewidth(0.7));
draw(interp(B,C,-0.2)--interp(B,C,1.2),linewidth(0.7));
draw(A--O--B,linewidth(0.7));
draw(D--P--C,linewidth(0.7));
label("$O$",O,SE);
label("$P$",P,E);
label("$D$",D,NW);
label("$A$",A,NW);
label("$B$",B,S);
label("$C$",C,S);
label("2",(-0.45,0.95),E);
label("6",(3,0),N);
label("4",(5.55,1.95),E);
[/asy]level
Level 5
type
Geometry
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