The rectangle is 84m long and 57m wide what is the length use the value 3.14 and do not round. ?

You need an answer, but we need a complete statement/description of the problem including all diagrams in order to give you that answer. An ill-phrased, incomplete question generates ill-phrased, incomplete answers.

I agree with your correspondent 'Puzzling' . Please give the full question. The use of the variable 'pi= 3.14' indicates that there is something to do with circles, which you have not mentioned in the question. 

If you want an accurate answer, you should include the whole question. While I'm not psychic, I'm guessing you have a rectangular field surrounded by an oval running track and they want the length of the running track.

The track is made up of two lengths as shown in green, and then two half-circles (equal to 1 full circle) with a radius of 28.5m as shown in blue.

L = 2 * 84 + 2π(28.5)

L = 168 + 57π

You can calculate the length *of the track* using your given approximation of π.

L ≈ 168 + 57(3.14)

L ≈ 346.98 m

If you use a more accurate value of π, you'd get a more accurate length. But personally, I would just say 347m and wouldn't add unnecessary precision despite what the question says.

The exact answer is (84/π) × π long

Kinda nonsensical but to each their own.

you have not asked a question that is meaningful.

If the question is "what is the length" ?, the answer is 84 m

Is this some kind of new math or something because since WHEN do you use pi for anything other than a circle 🤔

Um what? You said it's 84 meters long. And pi is used for circles, not rectangles.

Homework section is down the hall.