Mathematics · Grades 9–10
Trigonometry · Formula sheet
Rules, conditions and small examples in one printable reference.
Remember this
Sine in a right triangle
Name the angle first; opposite is the side across from that angle.
sin θ = opposite / hypotenuse
165/429 = 5/13
Tangent in a right triangle
The adjacent leg is next to the angle; it is not the hypotenuse.
tan θ = opposite / adjacent
32/18 = 16/9
Degrees and radians
A half turn is 180° or π radians.
radians = degrees × π/180
45 × π/180 = 1/4π
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.