Difference between revisions of "2011 AIME I Problems/Problem 8"
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In triangle <math>ABC</math>, <math>BC = 23</math>, <math>CA = 27</math>, and <math>AB = 30</math>. Points <math>V</math> and <math>W</math> are on <math>\overline{AC}</math> with <math>V</math> on <math> \overline{AW} </math>, points <math>X</math> and <math>Y</math> are on <math> \overline{BC} </math> with <math>X</math> on <math> \overline{CY} </math>, and points <math>Z</math> and <math>U</math> are on <math> \overline{AB} </math> with <math>Z</math> on <math> \overline{BU} </math>. In addition, the points are positioned so that <math> \overline{UV}\parallel\overline{BC} </math>, <math> \overline{WX}\parallel\overline{AB} </math>, and <math> \overline{YZ}\parallel\overline{CA} </math>. Right angle folds are then made along <math> \overline{UV} </math>, <math> \overline{WX} </math>, and <math> \overline{YZ} </math>. The resulting figure is placed on a level floor to make a table with triangular legs. Let <math>h</math> be the maximum possible height of a table constructed from triangle <math>ABC</math> whose top is parallel to the floor. Then <math>h</math> can be written in the form <math> \frac{k\sqrt{m}}{n} </math>, where <math>k</math> and <math>n</math> are relatively prime positive integers and <math>m</math> is a positive integer that is not divisible by the square of any prime. Find <math>k+m+n</math>. | In triangle <math>ABC</math>, <math>BC = 23</math>, <math>CA = 27</math>, and <math>AB = 30</math>. Points <math>V</math> and <math>W</math> are on <math>\overline{AC}</math> with <math>V</math> on <math> \overline{AW} </math>, points <math>X</math> and <math>Y</math> are on <math> \overline{BC} </math> with <math>X</math> on <math> \overline{CY} </math>, and points <math>Z</math> and <math>U</math> are on <math> \overline{AB} </math> with <math>Z</math> on <math> \overline{BU} </math>. In addition, the points are positioned so that <math> \overline{UV}\parallel\overline{BC} </math>, <math> \overline{WX}\parallel\overline{AB} </math>, and <math> \overline{YZ}\parallel\overline{CA} </math>. Right angle folds are then made along <math> \overline{UV} </math>, <math> \overline{WX} </math>, and <math> \overline{YZ} </math>. The resulting figure is placed on a level floor to make a table with triangular legs. Let <math>h</math> be the maximum possible height of a table constructed from triangle <math>ABC</math> whose top is parallel to the floor. Then <math>h</math> can be written in the form <math> \frac{k\sqrt{m}}{n} </math>, where <math>k</math> and <math>n</math> are relatively prime positive integers and <math>m</math> is a positive integer that is not divisible by the square of any prime. Find <math>k+m+n</math>. | ||
+ | |||
+ | <math>[asy] | ||
+ | unitsize(1 cm); | ||
+ | pair translate; | ||
+ | pair[] A, B, C, U, V, W, X, Y, Z; | ||
+ | A[0] = (1.5,2.8); | ||
+ | B[0] = (3.2,0); | ||
+ | C[0] = (0,0); | ||
+ | U[0] = (0.69*A[0] + 0.31*B[0]); | ||
+ | V[0] = (0.69*A[0] + 0.31*C[0]); | ||
+ | W[0] = (0.69*C[0] + 0.31*A[0]); | ||
+ | X[0] = (0.69*C[0] + 0.31*B[0]); | ||
+ | Y[0] = (0.69*B[0] + 0.31*C[0]); | ||
+ | Z[0] = (0.69*B[0] + 0.31*A[0]); | ||
+ | translate = (7,0); | ||
+ | A[1] = (1.3,1.1) + translate; | ||
+ | B[1] = (2.4,-0.7) + translate; | ||
+ | C[1] = (0.6,-0.7) + translate; | ||
+ | U[1] = U[0] + translate; | ||
+ | V[1] = V[0] + translate; | ||
+ | W[1] = W[0] + translate; | ||
+ | X[1] = X[0] + translate; | ||
+ | Y[1] = Y[0] + translate; | ||
+ | Z[1] = Z[0] + translate; | ||
+ | draw (A[0]--B[0]--C[0]--cycle); | ||
+ | draw (U[0]--V[0],dashed); | ||
+ | draw (W[0]--X[0],dashed); | ||
+ | draw (Y[0]--Z[0],dashed); | ||
+ | draw (U[1]--V[1]--W[1]--X[1]--Y[1]--Z[1]--cycle); | ||
+ | draw (U[1]--A[1]--V[1],dashed); | ||
+ | draw (W[1]--C[1]--X[1]); | ||
+ | draw (Y[1]--B[1]--Z[1]); | ||
+ | dot("</math>A<math>",A[0],N); | ||
+ | dot("</math>B<math>",B[0],SE); | ||
+ | dot("</math>C<math>",C[0],SW); | ||
+ | dot("</math>U<math>",U[0],NE); | ||
+ | dot("</math>V<math>",V[0],NW); | ||
+ | dot("</math>W<math>",W[0],NW); | ||
+ | dot("</math>X<math>",X[0],S); | ||
+ | dot("</math>Y<math>",Y[0],S); | ||
+ | dot("</math>Z<math>",Z[0],NE); | ||
+ | dot(A[1]); | ||
+ | dot(B[1]); | ||
+ | dot(C[1]); | ||
+ | dot("</math>U<math>",U[1],NE); | ||
+ | dot("</math>V<math>",V[1],NW); | ||
+ | dot("</math>W<math>",W[1],NW); | ||
+ | dot("</math>X<math>",X[1],dir(-70)); | ||
+ | dot("</math>Y<math>",Y[1],dir(250)); | ||
+ | dot("</math>Z<math>",Z[1],NE);[/asy]</math> |
Revision as of 20:45, 24 March 2011
In triangle , , , and . Points and are on with on , points and are on with on , and points and are on with on . In addition, the points are positioned so that , , and . Right angle folds are then made along , , and . The resulting figure is placed on a level floor to make a table with triangular legs. Let be the maximum possible height of a table constructed from triangle whose top is parallel to the floor. Then can be written in the form , where and are relatively prime positive integers and is a positive integer that is not divisible by the square of any prime. Find .
ABCUVWXYZUVWXYZ