Genesis 6:15

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

Genesis 7:20

Fifteen cubits upward did the waters prevail, and the mountains were covered.

Deuteronomy 3:11

For only Og, king of Bashan, had remained of the remnant of giants; behold, his bedstead was a bedstead of iron; is it not in Rabbath of the sons of Ammon? Nine cubits was the length thereof and four cubits the breadth of it, after 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
Fifteen cubits upward did the waters prevail, and the mountains were covered.
Deuteronomy 3:11
For only Og, king of Bashan, had remained of the remnant of giants; behold, his bedstead was a bedstead of iron; is it not in Rabbath of the sons of Ammon? Nine cubits was the length thereof and four cubits the breadth of it, after the cubit of a man.