The Longer Line
Two lines, exactly the same length, one wearing fins that point out and one wearing fins that point in. One looks plainly longer. Drag until they look equal, and WIZ measures how far the fins fooled you.
Each round shows two horizontal lines. One is fixed; the other has a slider (marked). One line wears arrowheads pointing outward, the other pointing inward.
Your only job: drag the slider until the two shafts look exactly the same length. Ignore the fins. Trust your eye, don’t try to measure the ends.
Eight quick rounds, about a minute. The catch: the fins bend how long each line looks, so the length you settle on will be off. WIZ measures exactly how far off, as a percentage.
Both lines are the same to me, exactly, every time. I read a shaft as the distance between its two endpoints; the fins are four more little segments sitting nearby, meaning nothing to the length. You are about to do the stranger thing: to see how long a line is, you will rebuild the whole small scene, and the scene will lie to you about the line.
About a minute. Match by eye, honestly, without hunting for the endpoints. Nothing is recorded or leaves this page.