MANOJ KUMAR SRIVASTAV. Semicircle : A Case Study on Concept of Trigonometrical Ratios of Acute Angles. International Journal of Mathematics And its Applications, [S. l.], v. 3, n. 4 - D, p. 75–78, 2015. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/517. Acesso em: 22 jul. 2024.