Introduction to Trigonometry Flashcards

Grade 9 · Math · Flashcards

Essential vocabulary and values for introductory trigonometry in Grade 9 Math.

Flashcards

SOH-CAH-TOA: Memory aid: sin=opp/hyp, cos=adj/hyp, tan=opp/adj
Sine: sin(θ) = opposite / hypotenuse
Cosine: cos(θ) = adjacent / hypotenuse
Tangent: tan(θ) = opposite / adjacent
Theta (θ): A Greek letter commonly used to name an unknown angle
Opposite side: The side across from the reference angle in a right triangle
Adjacent side: The side next to the reference angle (not the hypotenuse)
sin(30°): 1/2
cos(60°): 1/2
tan(45°): 1
Inverse sine (sin⁻¹): Returns the angle whose sine equals the given ratio
Angle of elevation: The angle measured upward from the horizontal to the line of sight