Categories
Intermediate

An odd wrapping

A present fits inside a circle, and we tape the orange ribbons to the green midpoints of the sides, choosing them perpendicular to the opposite sides at the purple points. Show that the four ribbons have a point in common.

Categories
Advanced

Spike

A triangle with two line segments. What’s the angle α?

Categories
Beginner

Pac-Man pack

Four Pac-Men eat the corners of a square while four others stand guard. What fraction of the square is eaten?