A point is chosen at random inside a square .
What is the probability that is acute?
Select one option, then click Submit.
\frac{3}{4}
\sqrt{2} - 1
\frac{1}{2}
\frac{\pi}{4}
1 - \frac{\pi}{8}
Select an option, then submit.
Sign in or create an account to reveal answers, view the solution, and save your progress. Create a free account to unlock practice and keep track of your work.
Senior Mathematical Challenge 2009 (2009)
One puzzle per day. Cryptarithm, Magic Square, Summit. No sign-up required to play.
Play daily puzzle →Interactive problems and curated lessons—water pouring, magic squares, knight's tour, and more.
Browse library →See how you rank. Top solvers by problems solved correctly. Sign in to climb the ranks.
View leaderboard →Senior Mathematical Challenge 2009 (2009)