Difference between revisions of "2006 AMC 12B Problems/Problem 15"

m
(Problem)
Line 2: Line 2:
  
 
== Problem ==
 
== Problem ==
{{problem}}
+
Circles with centers <math> O</math> and <math> P</math> have radii 2 and 4, respectively, and are externally tangent.  Points <math> A</math> and <math> B</math> are on the circle centered at <math> O</math>, and points <math> C</math> and <math> D</math> are on the circle centered at <math> P</math>, such that <math> \overline{AD}</math> and <math> \overline{BC}</math> are common external tangents to the circles.  What is the area of hexagon <math> AOBCPD</math>?
 +
 
 +
<asy>
 +
// from amc10 problem series
 +
unitsize(0.4 cm); defaultpen(linewidth(0.7) + fontsize(11));
 +
pair A, B, C, D;
 +
pair[] O;
 +
O[1] = (6,0);
 +
O[2] = (12,0);
 +
A = (32/6,8*sqrt(2)/6);
 +
B = (32/6,-8*sqrt(2)/6);
 +
C = 2*B;
 +
D = 2*A;
 +
draw(Circle(O[1],2));
 +
draw(Circle(O[2],4));
 +
draw((0.7*A)--(1.2*D));
 +
draw((0.7*B)--(1.2*C));
 +
draw(O[1]--O[2]);
 +
draw(A--O[1]);
 +
draw(B--O[1]);
 +
draw(C--O[2]);
 +
draw(D--O[2]);
 +
label("$A$", A, NW);
 +
label("$B$", B, SW);
 +
label("$C$", C, SW);
 +
label("$D$", D, NW);
 +
dot("$O$", O[1], SE);
 +
dot("$P$", O[2], SE);
 +
label("$2$", (A + O[1])/2, E);
 +
label("$4$", (D + O[2])/2, E);</asy>
 +
 
 +
<math> \textbf{(A) } 18\sqrt {3} \qquad \textbf{(B) } 24\sqrt {2} \qquad \textbf{(C) } 36 \qquad \textbf{(D) } 24\sqrt {3} \qquad \textbf{(E) } 32\sqrt {2}</math>
  
 
== Solution ==
 
== Solution ==

Revision as of 23:14, 28 October 2011

This is an empty template page which needs to be filled. You can help us out by finding the needed content and editing it in. Thanks.

Problem

Circles with centers $O$ and $P$ have radii 2 and 4, respectively, and are externally tangent. Points $A$ and $B$ are on the circle centered at $O$, and points $C$ and $D$ are on the circle centered at $P$, such that $\overline{AD}$ and $\overline{BC}$ are common external tangents to the circles. What is the area of hexagon $AOBCPD$?

[asy] // from amc10 problem series unitsize(0.4 cm); defaultpen(linewidth(0.7) + fontsize(11)); pair A, B, C, D; pair[] O; O[1] = (6,0); O[2] = (12,0); A = (32/6,8*sqrt(2)/6); B = (32/6,-8*sqrt(2)/6); C = 2*B; D = 2*A; draw(Circle(O[1],2)); draw(Circle(O[2],4)); draw((0.7*A)--(1.2*D)); draw((0.7*B)--(1.2*C)); draw(O[1]--O[2]); draw(A--O[1]); draw(B--O[1]); draw(C--O[2]); draw(D--O[2]); label("$A$", A, NW); label("$B$", B, SW); label("$C$", C, SW); label("$D$", D, NW); dot("$O$", O[1], SE); dot("$P$", O[2], SE); label("$2$", (A + O[1])/2, E); label("$4$", (D + O[2])/2, E);[/asy]

$\textbf{(A) } 18\sqrt {3} \qquad \textbf{(B) } 24\sqrt {2} \qquad \textbf{(C) } 36 \qquad \textbf{(D) } 24\sqrt {3} \qquad \textbf{(E) } 32\sqrt {2}$

Solution

See also

2006 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 14
Followed by
Problem 16
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions