Il risvolto ha la lunghezza corretta.

Because Italian is expressing the idea has the correct length, not is correct.

• ha = has
• è = is

So:

• Il risvolto ha la lunghezza corretta = The cuff/turn-up/lapel has the correct length
• Il risvolto è corretto would mean something more like The cuff/turn-up/lapel is correct, which is a broader and slightly different idea.

Italian often uses avere + noun in places where English might sometimes prefer an adjective.

Risvolto can have a few meanings depending on context, especially in clothing:

• a turn-up or cuff on trousers or sleeves
• a lapel
• more generally, a folded edge

So the exact English translation depends on what garment or object is being discussed. In a tailoring or clothing context, that is very normal.

Because lunghezza is a feminine singular noun, and here it needs the feminine singular definite article la.

• la lunghezza = the length

Italian uses articles more often than English does. In English, you might sometimes say has correct length only in a very technical or note-like style, but normal English would also usually say has the correct length.

Because corretta agrees with lunghezza, not with risvolto.

• lunghezza is feminine singular
• so the adjective must also be feminine singular: corretta

This is the structure:

• la lunghezza corretta
• noun: lunghezza
• adjective describing it: corretta

Even though risvolto is masculine, corretta is not describing risvolto directly. It is describing lunghezza.

Yes, that is also correct.

• Il risvolto ha la lunghezza corretta
• Il risvolto è della lunghezza corretta

Both mean essentially the same thing: the risvolto is the right length.

The version with ha is a bit more direct and straightforward. The version with è della lunghezza corretta can sound slightly more formal or descriptive.

Yes. La lunghezza giusta is very natural Italian.

Compare:

• la lunghezza corretta = the correct length
• la lunghezza giusta = the right length

In many everyday situations, giusta may sound a little more natural and conversational, while corretta can sound a bit more formal or technical.

In Italian, adjectives often come after the noun, especially when they classify or specify it in a clear, factual way.

So:

• la lunghezza corretta = normal, natural order

You sometimes can place adjectives before the noun in Italian, but that often changes the tone, emphasis, or style. In this sentence, lunghezza corretta is the most standard choice.

Normally, no—not in an ordinary complete sentence.

• Il risvolto ha la lunghezza corretta = normal full sentence

If you remove Il, you get Risvolto ha la lunghezza corretta, which is not standard Italian in normal usage.

You might see article omission only in special styles, such as:

• notes
• headings
• labels
• very telegraphic instructions

But in standard speech and writing, you should keep Il.

Because the sentence is specifically talking about the length as a measured property.

• ha la lunghezza corretta = has the correct length
• è lungo = it is long
• è corto = it is short

Using lunghezza makes the sentence more precise. It does not simply say whether something is long or short; it says that its length is the appropriate one.

Here is the structure:

• Il = masculine singular definite article, the
• risvolto = noun, masculine singular
• ha = third person singular of avere, has
• la = feminine singular definite article, the
• lunghezza = noun, feminine singular, length
• corretta = adjective, feminine singular, correct

So the pattern is:

• subject: Il risvolto
• verb: ha
• object/complement: la lunghezza corretta

A simple pronunciation guide would be:

eel reez-VOL-to ah lah loon-GHET-tsa kor-RET-ta

A few useful points:

• Il sounds like eel
• sv in risvolto is pronounced together smoothly
• gh in lunghezza makes a hard g sound, as in get
• zz in lunghezza sounds like ts
• the stress is on:
  • risVOLto
  • lunGHEZza
  • corRETta

Yes, but the original order is the most neutral and natural:

• Il risvolto ha la lunghezza corretta.

Italian can change word order for emphasis, but not every change sounds equally normal. For example, putting la lunghezza corretta first would sound marked and would usually need a specific context.

For a learner, the best version to use is the original one.