Difference between revisions of "2018 AIME I Problems/Problem 8"

(Solution Diagram)
(Solution Diagram)
Line 4: Line 4:
  
 
==Solution Diagram==
 
==Solution Diagram==
[asy]
+
[[image:2018_AIME_I-8.png|center|500px]]
draw((0,0)--(12,20.78)--(24,0)--cycle);
 
draw((1,1.73)--(2,0));
 
draw((9,15.59)--(15,15.59));
 
draw((14,0)--(19,8.66));
 
label("<math>A</math>",(9,15.59),NW);
 
label("<math>B</math>",(15,15.59),NE);
 
label("<math>C</math>",(19,8.66),NE);
 
label("<math>D</math>",(14,0),S);
 
label("<math>E</math>",(2,0),S);
 
label("<math>F</math>",(1,1.73),NW);
 
pair O;
 
O=(11.25,7.36);
 
dot(O);
 
label("<math>O</math>",O,SW);
 
draw(Circle(O,6.06));
 
[/asy]
 
asymptote code for a picture
 
 
- cooljoseph
 
- cooljoseph
 +
 
First of all, draw a good diagram! This is always the key to solving any geometry problem. Once you draw it, realize that <math>EF=2, FA=16</math>. Why? Because since the hexagon is equiangular, we can put an equilateral triangle around it, with side length <math>6+8+10=24</math>. Then, if you drew it to scale, notice that the "widest" this circle can be according to <math>AF, CD</math> is <math>7\sqrt{3}</math>.  And it will be obvious that the sides won't be inside the circle, so our answer is <math>\boxed{147}</math>.
 
First of all, draw a good diagram! This is always the key to solving any geometry problem. Once you draw it, realize that <math>EF=2, FA=16</math>. Why? Because since the hexagon is equiangular, we can put an equilateral triangle around it, with side length <math>6+8+10=24</math>. Then, if you drew it to scale, notice that the "widest" this circle can be according to <math>AF, CD</math> is <math>7\sqrt{3}</math>.  And it will be obvious that the sides won't be inside the circle, so our answer is <math>\boxed{147}</math>.
  
 
-expiLnCalc
 
-expiLnCalc

Revision as of 21:13, 7 March 2018

Let $ABCDEF$ be an equiangular hexagon such that $AB=6, BC=8, CD=10$, and $DE=12$. Denote $d$ the diameter of the largest circle that fits inside the hexagon. Find $d^2$.

Solutions

Solution Diagram

2018 AIME I-8.png

- cooljoseph

First of all, draw a good diagram! This is always the key to solving any geometry problem. Once you draw it, realize that $EF=2, FA=16$. Why? Because since the hexagon is equiangular, we can put an equilateral triangle around it, with side length $6+8+10=24$. Then, if you drew it to scale, notice that the "widest" this circle can be according to $AF, CD$ is $7\sqrt{3}$. And it will be obvious that the sides won't be inside the circle, so our answer is $\boxed{147}$.

-expiLnCalc