Trig Ratio Basics

Front

What is the definition of a trigonometric ratio?

Back

A trigonometric ratio is a ratio of the lengths of two sides of a right triangle. The primary trigonometric ratios are sine, cosine, and tangent.

Front

What is the sine ratio?

Back

The sine ratio is defined as the length of the opposite side divided by the length of the hypotenuse (sin(θ) = opposite/hypotenuse).

Front

What is the cosine ratio?

Back

The cosine ratio is defined as the length of the adjacent side divided by the length of the hypotenuse (cos(θ) = adjacent/hypotenuse).

Front

What is the tangent ratio?

Back

The tangent ratio is defined as the length of the opposite side divided by the length of the adjacent side (tan(θ) = opposite/adjacent).

Front

Identify the hypotenuse in a right triangle.

Back

The hypotenuse is the longest side of a right triangle, opposite the right angle.

Front

If sin(θ) = 0.5, what is the angle θ?

Back

θ = 30° (or π/6 radians).

Front

What is the relationship between sine and cosine?

Back

Sine and cosine are complementary functions: sin(θ) = cos(90° - θ).

Front

How do you find the length of the opposite side using the sine ratio?

Back

To find the opposite side, use the formula: opposite = hypotenuse × sin(θ).

Front

How do you find the length of the adjacent side using the cosine ratio?

Back

To find the adjacent side, use the formula: adjacent = hypotenuse × cos(θ).

Front

What is the formula for the tangent ratio?

Back

The formula for tangent is tan(θ) = opposite/adjacent.