A semicircle with three tangents. The tangency points are shown. Prove that the red line segments are concurrent.
Scroll down for a solution to this problem.
Solution

Both the intersection point of red diagonals and the tangent point on the circle have the same horizontal distance to the perpendicular tangent on the left. Hence a perpendicular line from tangent point to the diameter goes through the intersection point.
Poem
No pasaran
Famous slogan
Famous argument
Spoken by the oppressed people
A warning for the enemy
To stop the dictators
And prevent death
To avoid civil suffering
Two words
No pasaran
