Cross reference
Genesis 6:15
15 And this is the way you are to make it: it is to be three hundred cubits long, fifty cubits wide, and thirty cubits high.
Genesis 7:20
20 The waters went fifteen cubits higher, till all the mountains were covered.
Deuteronomy 3:11
11 (For Og, king of Bashan, was the last of all the Rephaim; his bed was made of iron; is it not in Rabbah, in the land of the children of Ammon? It was nine cubits long and four cubits wide, measured by the common cubit.)