Right Triangle Trig

Front

What is the definition of cosine in a right triangle?

Back

Cosine (cos) of an angle is the ratio of the length of the adjacent side to the length of the hypotenuse.

Front

What is the definition of sine in a right triangle?

Back

Sine (sin) of an angle is the ratio of the length of the opposite side to the length of the hypotenuse.

Front

What is the definition of tangent in a right triangle?

Back

Tangent (tan) of an angle is the ratio of the length of the opposite side to the length of the adjacent side.

Front

What does SOH CAH TOA stand for?

Back

SOH: Sine = Opposite/Hypotenuse, CAH: Cosine = Adjacent/Hypotenuse, TOA: Tangent = Opposite/Adjacent.

Front

If cos X = 28/41, what is the value of sin X?

Back

sin X = √(1 - cos²X) = √(1 - (28/41)²) = 33/41.

Front

How do you find the angle using cosine?

Back

Use the inverse cosine function: X = cos⁻¹(adjacency/hypotenuse).

Front

What is the relationship between sine and cosine?

Back

sin²X + cos²X = 1 for any angle X.

Front

If tan X = 3/4, what are the lengths of the opposite and adjacent sides?

Back

Opposite = 3k, Adjacent = 4k for some k.

Front

What is the value of sin(30°)?

Back

sin(30°) = 1/2.

Front

What is the value of cos(60°)?

Back

cos(60°) = 1/2.