Ezekiel 43:16

Now the altar hearth shall be twelve cubits long by twelve wide, square in its four sides.

Exodus 27:1

“And you shall make the altar of acacia wood, five cubits long and five cubits wide; the altar shall be square, and its height shall be three cubits.

Exodus 38:1-2

Then he made the altar of burnt offering of acacia wood, five cubits long, and five cubits wide, square, and three cubits high.

2 Chronicles 4:1

Then he made a bronze altar, twenty cubits in length and twenty cubits in width and ten cubits in height.

Ezra 3:3

So they set up the altar on its foundation, for they were terrified because of the peoples of the lands; and they offered burnt offerings on it to the Lord, burnt offerings morning and evening.

Treasury of Scripture Knowledge

Summary

And the altar shall be twelve cubits long, twelve broad, square in the four squares thereof.

Square

Bible References

Twelve cubits

Exodus 27:1
“And you shall make the altar of acacia wood, five cubits long and five cubits wide; the altar shall be square, and its height shall be three cubits.
2 Chronicles 4:1
Then he made a bronze altar, twenty cubits in length and twenty cubits in width and ten cubits in height.
Ezra 3:3
So they set up the altar on its foundation, for they were terrified because of the peoples of the lands; and they offered burnt offerings on it to the Lord, burnt offerings morning and evening.

Square

Exodus 38:1
Then he made the altar of burnt offering of acacia wood, five cubits long, and five cubits wide, square, and three cubits high.