Learn Hardcore Italian: Misuriamo la distanza tra le città. - We measure the distance between the cities.

So grammatically it is the noi form, meaning we measure or we are measuring, depending on context. Italian often uses the simple present where English might use either the simple present or the present continuous.

Can misuriamo also mean let's measure?

Yes. In Italian, the noi imperative often has the same form as the present indicative, so misuriamo can also mean let's measure.

That means this form can be understood in two ways:

statement: we measure / we are measuring
suggestion or command: let's measure

Punctuation and context usually make the meaning clear. With a normal full stop, learners will usually read it as a statement.

Why is it la distanza and not just distanza?

Italian uses definite articles more often than English does. In a sentence like this, la distanza is the natural way to say the distance.

Without la, the sentence would sound incomplete or unnatural in standard Italian.

Why is distanza singular?