No 1847 Sangaku Problem

Geometry Level 5

In the large circle, five circles - four large green and one small orange - are mutually tangent to each other. As shown above, two green circles are tangent to the base of the inscribed isosceles triangle, containing three circles. Two cyan ellipses, both of the maximum possible eccentricity, are each tangent to the leg of the triangle as well as the circumference of the large circle - each side at one point. In addition, their major axes are parallel to their respective leg of the triangle.

If the following ratio can be expressed as

major axis of the ellipse diameter of the orange circle = A B ( C + D E ) \dfrac{\text{major axis of the ellipse}}{\text{diameter of the orange circle}} = \dfrac{A}{B}\left(C + D\sqrt{E}\right)

where A , B , C , D , E A,B,C,D,E are positive integers, gcd ( A , B ) = gcd ( C , D ) = 1 \gcd(A,B) = \gcd(C,D) = 1 and E E is square-free, input A + B + C + D + E A + B + C + D + E as your answer.


The answer is 54.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

0 solutions

No explanations have been posted yet. Check back later!

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...