Class-X Trigonometry Assamese medium part-5 by Rahimuddin Sheikh

Class-X Trigonometry Assamese medium part-5 by Rahimuddin Sheikh

6. যদি ∠A আৰু ∠B সূক্ষ্মকোণ হয় যাতে cosA = cosB, তেম্ত দেখুওৱা যে ∠A=∠B