How to type array of array of numbers in typescript?

Question

I want to type array of any number of arrays with 3 coordinates each :

[[1,2,3], [4,5,6],...]

I'd like something like this except it doesn't work

Array<Array<Number,Number,Number>>

Answer 1

Playground

type MyArray = [number, number, number][];

const test1: MyArray = [[1, 2, 3]];
const test2: MyArray = [[1, 2, 3], [4, 5, 6]];
const test3: MyArray = [[1, 2, 3], [1]]; // error
const test4: MyArray = [[1, 2, 3], [4, 5, 6, 7]]; // error