Common Core Geometry.Unit #8.Lesson #2.The Trigonometric Ratios

In this lesson we introduce the trigonometric ratios by first examining two similar right triangles that are different sizes. We see how the ratios of relatively positioned sides of these triangles are equal and only depend on an acute angle of the triangle. We see how this then gives rise to the three trigonometric ratios of sine, cosine, and tangent.