Art of Problem Solving

1959 AHSME Problems/Problem 41: Difference between revisions

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== Solution ==
== Solution ==
<asy>
import geometry;
point A = (0,4);
point B = (-16,16);
point C = (16,16);
point D = (-16,0);
point E = (16,0);
point F = (0,16);
// The line
line l = line((-20,0),(20,0));
draw(l, Arrows);
// Circles
draw(circle(A,4));
dot(A);
label("A",A,(0,-3));
draw(circle(B,16));
dot(B);
label("B",B,W);
draw(circle(C,16));
dot(C);
label("C",C,(1,0));
//Tangency points
dot(D);
label("D",D,S);
dot(E);
label("E",E,S);
dot(F);
label("F",F,NE);
// Triangle AFB, Segment BD
draw(triangle(A,F,B));
draw(B--D);
// Right angle labels
markscalefactor=0.3;
draw(rightanglemark(F,B,D));
draw(rightanglemark(B,D,E));
</asy>
<math>\fbox{D}</math>
<math>\fbox{D}</math>



Revision as of 18:21, 21 July 2024

Problem

On the same side of a straight line three circles are drawn as follows: a circle with a radius of $4$ inches is tangent to the line, the other two circles are equal, and each is tangent to the line and to the other two circles. The radius of the equal circles is: $\textbf{(A)}\ 24 \qquad\textbf{(B)}\ 20\qquad\textbf{(C)}\ 18\qquad\textbf{(D)}\ 16\qquad\textbf{(E)}\ 12$

Solution

[asy]  import geometry;  point A = (0,4); point B = (-16,16); point C = (16,16); point D = (-16,0); point E = (16,0); point F = (0,16);  // The line line l = line((-20,0),(20,0)); draw(l, Arrows);  // Circles draw(circle(A,4)); dot(A); label("A",A,(0,-3)); draw(circle(B,16)); dot(B); label("B",B,W); draw(circle(C,16)); dot(C); label("C",C,(1,0));  //Tangency points dot(D); label("D",D,S); dot(E); label("E",E,S); dot(F); label("F",F,NE);  // Triangle AFB, Segment BD draw(triangle(A,F,B)); draw(B--D);  // Right angle labels markscalefactor=0.3; draw(rightanglemark(F,B,D)); draw(rightanglemark(B,D,E));  [/asy]

$\fbox{D}$

See also

1959 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 40
Followed by
Problem 42
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 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
All AHSME Problems and Solutions

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