Perceptle Angle practice
Match the angle.
Drag counterclockwise from the right-hand line. Release to submit.
Use a slider instead
Independent normal-mode practice · Best saved on this device
Start with a few familiar directions.
- Press Start to receive a random target between 5° and 355°.
- The right-facing baseline is 0°. Drag the handle counterclockwise around the circle. Up is 90°, left is 180°, and down is 270°.
- Release to submit. Compare your line with the dashed green target and read the shortest angular difference.
A useful way to improve
Anchor your estimate to 90°, 180°, and 270°, then judge the remaining piece. For 150°, think 30° short of the left-facing line. Near 360°, remember that the line is almost back at its starting direction.
What the score means
Normal practice uses an 8° tolerance and the shortest circular difference. A 359° guess for a 5° target is 6° away, not 354°. This exercise stays within one turn; Friday’s original event can use angles beyond a full turn.
Every score is out of 100. A fresh target appears each round, and your best for this exercise stays in your browser. Read the score curve and grade thresholds for worked examples.
Touch and keyboard controls
Drag anywhere on the circular field and release to lock your angle. Open “Use a slider instead” to adjust with arrow keys, Home or End, then press Lock angle. Scrolling works normally outside the field.
If you switch apps or hide the page during an active round, it stops without recording a score. Resize the window freely: targets are drawn in the same logical field and saved results remain intact.
Teaching examples · not today’s puzzle or an official answer
Angle example: anchor the turn, then judge the small part.
The normal round measures counterclockwise from the right-facing line. Four familiar directions divide the turn: right 0°, up 90°, left 180°, down 270°. For a 150° target, start with the left-facing 180° direction and move back 30° toward up.
Read one result near 0°
Target: 5°. Your line: 359°. The short way crosses the starting direction: 359° → 360°/0° → 5°. That is 1° + 5° = 6°, not 354°. With an 8° tolerance, it scores 75 / 100.
In the result, the dashed green line is the target. A short gap near the right-facing baseline is still a small error, even when the displayed numbers sit far apart.
Change one thing next round
Name the nearest reference direction before dragging. If a 150° request repeatedly lands near 210°, check the counterclockwise direction rather than treating it as a small estimation problem. For near-zero targets, compare the short wedge across the baseline. Release the handle only after judging that wedge.
Try Angle using a reference direction ↑Diagnose repeated Angle errors →Handle Friday angles beyond one full turn →Another way to trust your instincts.
Try Tempo