Question

Find cos (B) in the triangle

Answer 1

Basic Trigonometric Ratios

We can identify the sides of a right triangle by describing their location in relation to a given angle.

• The "hypotenuse" is the longest side of a right triangle. It is opposite the right angle.
• The "opposite" is the side that the angle does not touch.
• The "adjacent" is the side that the angle does touch, that is not the hypotenuse.

There are three basic trigonometric ratios:

• The sine ratio:
  `\sin\theta=(opposite)/(hypotenuse)`
• The cosine ratio:
  `\cos\theta=(adjacent)/(hypotenuse)`
• The tangent ratio:
  `\tan\theta=(opposite)/(adjacent)`

We use theta (θ) to represent an angle.

Solving the Question

We are asked to find
`\cos(\beta)` in the triangle.

`\cos\theta=(adjacent)/(hypotenuse)`

The side adjacent to β measures 8 units.

The hypotenuse of the right triangle measures 17 units.

`\cos\beta=(8)/(17)`

Answer

Therefore,
`\cos\beta=(8)/(17)`.