Two modes
- Guess the angle: type how many degrees the shaded angle between two lines is. Angles run from 10° to 350° and the drawing is rotated at random.
- Make the angle: you are given a number of degrees and drag a line to make that angle, measured counterclockwise from the fixed line.
Scoring
Each round scores 10 × e^(−error ÷ 8): 1° off earns about 8.8, 4° about 6.1 and 8° about 3.7. Ten rounds add up to 100.
Tips
- Keep reference angles in mind: a right angle (90°), half of it (45°), and the 60° corner of an equilateral triangle.
- Think of a clock face. Each hour mark is 30° apart.
- For angles over 180°, work out what is left over from 360°.
Vision research has reported a tendency to see acute angles as a little larger and obtuse angles as a little smaller than they are. See whether your results lean the same way.