Question

The cosine of an angle is the ratio of the opposite side over the hypotenuse.

a. True
b. False

Answer 1

It's False.Sine is a trigonometric function of the angle in a right triangle is equal to the ratio of the opposite leg to the angle of the hypotenuse.

Answer 2

False, The cosine of an angle is the ratio of the opposite side over the hypotenuse.

Let ΔABC is a right angled triangle, ∠C = 90°

Figure is attached.

let ∠B be
`\theta`

Then the trigonometric ratios are the following:

`sin\,\theta=(AC)/(AB)`

`cos\,\theta=(CB)/(AB)`

`tan\,\theta=(AC)/(CB)`

`cosec\,\theta=(AB)/(AC)`

`sec\,\theta=(AB)/(CB)`

`tan\,\theta=(CB)/(AC)`

So, clearly
`cos\,\theta=(Adjacent)/(Hypotenuse)`

Its
`sin\,\theta=(Opposite)/(Hypotenuse)`