Trigonometric Ratios Of Some Special Angles — Chapter Summary

For an acute angle C

For an acute angle C in a right triangle, sin C = opposite/hypotenuse, cos C = adjacent/hypotenuse, tan C = opposite/adjacent, and their reciprocals a

In a right triangle ABC right

In a right triangle ABC right-angled at B, AC^2 = AB^2 + BC^2.

In the 45° construction

In the 45° construction, the right triangle has equal legs, so if each leg is a units, the hypotenuse is (sqrt(2))a. Therefore sin 45° = cos 45° = 1/(

In the 30° construction

In the 30° construction, an equilateral triangle is formed and then split into two right triangles. The resulting values are sin 30° = 1/2, cos 30° =

In the 60° construction

In the 60° construction, another equilateral triangle is formed. The resulting values are sin 60° = (sqrt(3))/2, cos 60° = 1/2, tan 60° = sqrt(3), cos