Japan Math Olympiad | Can You Solve This? | Two Hidden Circles

Can you solve this Japan Math Olympiad problem? A triangle with ∠EDF = 180° − ½∠A and two perpendicular bisectors: find the area of triangle DPQ? (2026 Japan Mathematical Olympiad, preliminary round, Problem 9.) A full step-by-step solution for middle and high school students: we try small cases, find the key idea, prove every step and check the answer. Pause and try it first! ⏱ Chapters 0:00 Intro 2:09 Understanding the problem 3:14 The key idea: hidden circles 6:11 Where is R? 8:06 Two isosceles triangles 9:29 The area, and a check 10:37 Takeaways ▶ Watch next • Japan Math Olympiad 2026, Problem 8:    • Japan Math Olympiad | Can You Solve This? ...   • Japan Math Olympiad 2026, Problem 1: a²⁰ + b² + c⁶ = 2026:    • Japan Math Olympiad | Can You Solve This? ...   🔔 Subscribe for more:    / @hardnumberstv   📚 Key ideas • P and Q are secretly circumcentres • Inscribed-angle chase puts R on the circumcircle • Two isosceles triangles give the lengths • Answer: 48√7/25 📖 Source Problem: 2026 Japan Mathematical Olympiad, Preliminary Round (held Nov 16, 2025), Problem 9. © Mathematical Olympiad Foundation of Japan. Problem restated in English for commentary and education; the solution and explanation are our own, checked by computer against the official answer. Characters are cartoon illustrations. Narration: AI voice. Music and sound effects: original. 💬 How did you solve it? Tell me in the comments. #MathOlympiad #Math #Puzzle