Genesis 6:15

And this [is] how you must make it: the length of the ark, three hundred cubits; its width fifty cubits; its height, thirty cubits.

Genesis 7:20

{The waters swelled fifteen cubits above the mountains, covering them}.

Deuteronomy 3:11

(For only Og, king of Bashan, was left from the remnant of the Rephaim. Indeed, his bedstead--it [was] a bedstead of iron. It is in Rabbah of the {Ammonites}. Nine cubits [is] its length, and four cubits [is] its width according to the cubit of a man.)

Treasury of Scripture Knowledge

Summary

And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.

Bible References

Cubits

Genesis 7:20
{The waters swelled fifteen cubits above the mountains, covering them}.
Deuteronomy 3:11
(For only Og, king of Bashan, was left from the remnant of the Rephaim. Indeed, his bedstead--it [was] a bedstead of iron. It is in Rabbah of the {Ammonites}. Nine cubits [is] its length, and four cubits [is] its width according to the cubit of a man.)