Resolução de Exercícios: Razões Trigonométricas no Triângulo Retângulo Parte 2

Synopsis: In this lesson we continue with solving exercises involving trigonometric ratios in right triangles. Among other things we also use the similar triangles. At the end prove that the square of the sine over the square of the cosine is equal to the angle independently. This relationship is known as trigonometry fundamental relationship.
Source: Portal of Mathematics.
URL: http://matematica.obmep.org.br/index.php/modulo/ver?modulo=11#