In this page, the trigonometric ratios defined in triangular form is revised.

Note: The trigonometric ratios are also called trigonometric values and are defined in unit circle form. This will be explained in advanced trigonometry.

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Let us quickly review the terminology in trigonometric ratios.

Which side is the hypotenuse?

- `bar(PQ)`
- `bar(QR)`
- `bar(PR)`
- `bar(PR)`

The answer is '`bar(PR)`'

Which side is the opposite side to `/_theta`?

- `bar(PQ)`
- `bar(QR)`
- `bar(QR)`
- `bar(PR)`

The answer is '`bar(QR)`'

Which side is the adjacent side to `/_theta`?

- `bar(PQ)`
- `bar(PQ)`
- `bar(QR)`
- `bar(PR)`

The answer is '`bar(PQ)`'

Which side is the opposite side to `/_theta`?

- `bar(PQ)`
- `bar(PQ)`
- `bar(QR)`
- `bar(PR)`

The answer is '`bar(PQ)`'

Which side is the adjacent side to `/_theta`?

- `bar(PQ)`
- `bar(QR)`
- `bar(QR)`
- `bar(PR)`

The answer is '`bar(QR)`'

Which side is the hypotenuse?

- `bar(AB)`
- `bar(AB)`
- `bar(BC)`
- `bar(AC)`

The answer is '`bar(AB)`'

Which side is the hypotenuse?

- `bar(AB)`
- `bar(BC)`
- `bar(AC)`
- `bar(AC)`

The answer is '`bar(AC)`'

Which side is the opposite side to `/_theta`?

- `bar(AB)`
- `bar(BC)`
- `bar(AC)`

The answer is '`bar(BC)`'

Which side is the adjacent side to `/_theta`?

- `bar(AB)`
- `bar(BC)`
- `bar(BC)`
- `bar(PR)`

The answer is '`bar(BC)`'

What is `sin theta`?

- `text(opposite)/text(hypotenuse)`
- `text(opposite)/text(hypotenuse)`
- `text(adjacent)/text(hypotenuse)`

The answer is '`text(opposite)/text(hypotenuse)`'

What is `cos theta`?

- `text(opposite)/text(hypotenuse)`
- `text(adjacent)/text(hypotenuse)`
- `text(adjacent)/text(hypotenuse)`

The answer is '`text(adjacent)/text(hypotenuse)`'

What is `tan theta`?

- `text(opposite)/text(hypotenuse)`
- `text(adjacent)/text(hypotenuse)`
- `text(adjacent)/text(hypotenuse)`
- `text(opposite)/text(adjacent)`

The answer is '`text(opposite)/text(adjacent)`'

Which of the following is equivalently `tan theta`?

- `1/ (sin theta)`
- `1/(cos theta)`
- `1/(cos theta)`
- `(sin theta)/(cos theta)`

The answer is '`(sin theta)/(cos theta)`'

Revising the definition of trigonometric ratios

`sin theta = text(opposite)/text(hypotenuse)`

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

`tan theta = text(opposite)/text(adjacent)`

What is `1/(cos theta)`?

- `text(hypotenuse)/text(opposite)`
- `text(hypotenuse)/text(adjacent)`
- `text(hypotenuse)/text(adjacent)`

The answer is '`text(hypotenuse)/text(adjacent)`'

`1/(cos theta)` is called as '`sec theta`'.

`sec theta`

`quad quad = text(hypotenuse)/text(adjacent)`

`quad quad = 1/ (cos theta)`

What is `1/(sin theta)`?

- `text(hypotenuse)/text(opposite)`
- `text(hypotenuse)/text(opposite)`
- `text(hypotenuse)/text(adjacent)`

The answer is '`text(hypotenuse)/text(opposite)`'

`1/(sin theta)` is called as '`text(cosec) theta`' or '`csc theta`'.

`text(cosec) theta` or `csc theta`

`quad quad = text(hypotenuse)/text(opposite)`

`quad quad = 1/ (sin theta)`

What is `1/(tan theta)`?

- `text(opposite)/text(adjacent)`
- `text(adjacent)/text(opposite)`
- `text(adjacent)/text(opposite)`

The answer is '`text(adjacent)/text(opposite)`'

`1/(tan theta)` is called as '`cot theta`'.

`text(tan) theta`

`quad quad = text(adjacent)/text(opposite)`

`quad quad = 1/ (tan theta)`

**Trigonometric Ratios: **

`sin theta = text(opposite)/text(hypotenuse)`

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

`tan theta = text(opposite)/text(adjacent)`

`sec theta = text(hypotenuse)/text(adjacent)`

`text(cosec) theta = text(hypotenuse)/text(opposite)`

`cot theta = text(adjacent)/text(opposite)`

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