Angle Puzzles
Find the angle marked “?”. No protractor needed — you can solve it from the properties of the shapes alone. Stuck? Open the hints one step at a time.
Hidden in a straight line
Two straight lines cross. What is the angle marked ?
Numbers are known angles; ? is the angle to find.
How to play
Enter the angle marked ? and check your answer. No protractor needed. Open hints one at a time whenever you want a fresh idea. Use the numbered buttons to revisit any puzzle.
Learn more
Explore 100 puzzles across seven levels: 1, lines and triangles; 2, equal sides and exterior angles; 3, parallel lines; 4, polygons; 5, circles; 6, combinations including folds and bisectors; and 7, challenges with a fresh way of seeing. Some hints add a line or circle to reveal a new idea. Solved puzzles are saved in this browser, and play still works when storage is unavailable.