Ezekiel 43:16

and it was twelve cubits long and twelve cubits broad, upon the four corners.

Exodus 27:1

And thou shalt make an altar of sethim-wood: five cubits long and five cubits broad, that it be foursquare, and three cubits high.

Exodus 38:1-2

And he made the burnt offering altar of sethim-wood, five cubits long and five cubits broad: even four square, and three cubits high.

2 Chronicles 4:1

And he made an altar of brass twenty cubits long and twenty cubits broad and ten cubits high.

Ezra 3:3

And the altar set they upon his sockets - for there was a fearfulness among them because of the nations and the lands - and offered burnt offerings thereon unto the LORD, in the morning and at 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 thou shalt make an altar of sethim-wood: five cubits long and five cubits broad, that it be foursquare, and three cubits high.
2 Chronicles 4:1
And he made an altar of brass twenty cubits long and twenty cubits broad and ten cubits high.
Ezra 3:3
And the altar set they upon his sockets - for there was a fearfulness among them because of the nations and the lands - and offered burnt offerings thereon unto the LORD, in the morning and at evening.

Square

Exodus 38:1
And he made the burnt offering altar of sethim-wood, five cubits long and five cubits broad: even four square, and three cubits high.