Difference between revisions of "1969 AHSME Problems/Problem 10"

(Created page with "== Problem == The number of points equidistant from a circle and two parallel tangents to the circle is: <math>\text{(A) } 0\quad \text{(B) } 2\quad \text{(C) } 3\quad \text{(D...")
 
(Solution to Problem 10)
 
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== Solution ==
 
== Solution ==
<math>\fbox{C}</math>
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<asy>
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draw(circle((0,0),100));
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draw((-300,100)--(300,100),Arrows);
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draw((-300,-100)--(300,-100),Arrows);
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draw((-300,0)--(300,0),dotted,Arrows);
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dot((-200,0));
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dot((0,0));
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dot((200,0));
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draw((-200,100)--(-200,-100),dotted);
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draw((200,100)--(200,-100),dotted);
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</asy>
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The distance between the two parallel tangents is the length of the circle's diameter, so the distance from a point that satisfies the conditions and the two tangents is the length of the circle's radius.  From the diagram, there are <math>\boxed{\textbf{(C) } 3}</math> points that satisfies the conditions.
  
 
== See also ==
 
== See also ==
{{AHSME box|year=1969|num-b=9|num-a=11}}   
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{{AHSME 35p box|year=1969|num-b=9|num-a=11}}   
  
 
[[Category: Introductory Geometry Problems]]
 
[[Category: Introductory Geometry Problems]]
 
{{MAA Notice}}
 
{{MAA Notice}}

Latest revision as of 04:01, 7 June 2018

Problem

The number of points equidistant from a circle and two parallel tangents to the circle is:

$\text{(A) } 0\quad \text{(B) } 2\quad \text{(C) } 3\quad \text{(D) } 4\quad \text{(E) } \infty$

Solution

[asy] draw(circle((0,0),100)); draw((-300,100)--(300,100),Arrows); draw((-300,-100)--(300,-100),Arrows); draw((-300,0)--(300,0),dotted,Arrows); dot((-200,0)); dot((0,0)); dot((200,0)); draw((-200,100)--(-200,-100),dotted); draw((200,100)--(200,-100),dotted); [/asy] The distance between the two parallel tangents is the length of the circle's diameter, so the distance from a point that satisfies the conditions and the two tangents is the length of the circle's radius. From the diagram, there are $\boxed{\textbf{(C) } 3}$ points that satisfies the conditions.

See also

1969 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 9
Followed by
Problem 11
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
All AHSME Problems and Solutions

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