Skip to main content
OlympiadHQ

Browse · MathNet

Print

Selection and Training Session

Belarus geometry

Problem

Given the parallelogram . The circle passes through the vertex and touches the sides and at points and respectively. The circle passes through the vertex and touches the sides and at points and respectively. Let be the distances from and to the lines and respectively. Find all possible values of the ratio .
Solution
Answer : 1. We prove that . Let , . Choose points and on so that . Then . Further, , thus we have . Similarly, , so . Multiplying these equalities we have . Note that is the length of the altitude in , so , or

In the same way we obtain that , as required.
Final answer
1

Techniques

TangentsAngle chasingQuadrilaterals