2008 AIME I Problems/Problem 10
Problem
Let be an isosceles trapezoid with whose angle at the longer base is . The diagonals have length , and point is at distances and from vertices and , respectively. Let be the foot of the altitude from to . The distance can be expressed in the form , where and are positive integers and is not divisible by the square of any prime. Find .
Solution
Applying the triangle inequality to , we see that On the other hand, if is strictly greater than , then the circle with radius and center does not touch , which implies that , a contradiction. Hence It follows that are collinear, and also that and are 30-60-90 triangles. Hence , and Hence the answer to this problem is 25+7, or 32.
See also
2008 AIME I (Problems • Answer Key • Resources) | ||
Preceded by Problem 9 |
Followed by Problem 11 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 | ||
All AIME Problems and Solutions |