Тихая зона закрыта, в то время как общая зона открыта.

Because they agree with зона, which is a feminine singular noun in the nominative case.

• тихий = quiet
• общий = common / general / shared
• зона = zone

When these adjectives describe зона, they must match it:

• masculine: тихий
• feminine: тихая
• neuter: тихое
• plural: тихие

So:

• тихая зона = quiet zone
• общая зона = common/shared zone

Закрыта and открыта are short-form adjectives. In Russian, short-form adjectives are often used to describe a current state:

• зона закрыта = the zone is closed
• зона открыта = the zone is open

The full forms закрытая and открытая usually describe a noun more like a regular attribute:

• закрытая зона = a closed zone
• открытая зона = an open zone

So in this sentence:

• Тихая зона закрыта means The quiet zone is closed
• not The closed quiet zone

Yes. Short-form adjectives still agree in gender and number.

Since зона is feminine singular, we get:

• masculine: закрыт, открыт
• feminine: закрыта, открыта
• neuter: закрыто, открыто
• plural: закрыты, открыты

For example:

• Магазин открыт = The store is open
• Дверь открыта = The door is open
• Окно открыто = The window is open
• Двери открыты = The doors are open

In the present tense, Russian normally omits the verb to be.

So:

• Тихая зона закрыта literally looks like Quiet zone closed
• but it means The quiet zone is closed

This is completely normal in Russian.

If you were speaking about the past or future, a form of быть would appear:

• Тихая зона была закрыта = The quiet zone was closed
• Тихая зона будет закрыта = The quiet zone will be closed

В то время как means while, whereas, or while at the same time.

In this sentence, it introduces a contrast:

• Тихая зона закрыта, в то время как общая зона открыта.
• The quiet zone is closed, whereas the common area is open.

This expression is a bit more formal and explicit than just using а.

Compare:

• Тихая зона закрыта, а общая зона открыта. = The quiet zone is closed, but/the common zone is open.
• Тихая зона закрыта, в то время как общая зона открыта. = The quiet zone is closed, whereas the common zone is open.

Because в то время как introduces a subordinate clause, and Russian uses a comma to separate it from the main clause.

So the structure is:

• Тихая зона закрыта,
• в то время как общая зона открыта

This comma is required in standard Russian punctuation.

Общая зона literally means something like common zone, general zone, or shared area.

Depending on context, it could be translated as:

• common area
• general area
• shared space
• public area

A native English translation often depends on the setting:

• in a library: general area
• in an office or building: common area
• in a waiting space: shared area

So the Russian is straightforward, but the best English wording may vary a little by context.

Yes. Russian word order is fairly flexible, so you could say:

• Общая зона открыта, в то время как тихая зона закрыта.

This means the same basic thing, but the emphasis changes slightly. The clause that comes first often feels more prominent or like the starting point of the message.

So:

• Тихая зона закрыта... focuses first on the quiet zone
• Общая зона открыта... focuses first on the common zone

Yes, it is understandable and natural, especially in signs or formal descriptions. It means quiet zone.

However, depending on the context, Russian might also use other expressions, such as:

• зона тишины = quiet zone / silence zone
• тихое место = quiet place
• место для тишины = place for quiet

In signage or public-space language, тихая зона works well.

Both instances of зона are in the nominative singular because they are the subjects of their clauses:

• Тихая зона закрыта
• общая зона открыта

The adjectives тихая and общая also appear in the nominative feminine singular to match зона.

The short-form adjectives закрыта and открыта do not show case the way full adjectives do, but they still agree in gender and number with the subject.

Yes, but the tone changes.

• Тихая зона закрыта, но общая зона открыта.
• The quiet zone is closed, but the common area is open.

This is natural and simpler.

Compare the conjunctions:

• но = but
• а = and/but, often for contrast
• в то время как = while/whereas, more explicit and sometimes more formal

So но is possible, but в то время как sounds a bit more structured and written.