The 30°-60°-90° triangle. Topics in trigonometry.
4 THE 30 -60 -90 TRIANGLE THERE ARE TWO special triangles in trigonometry. One is the 30 -60 -90 triangle. The other is the isosceles right triangle. They are special because, with simple geometry, we can know the ratios of their sides. Theorem. In a 30 ....