The Square

The Square

A right angle is the most important shape on a job site. The square keeps it honest.

3-4-5. Egyptian rope-stretchers and every carpenter since: a triangle with sides 3, 4 and 5 has a right angle.

The try square. A wooden stock and a steel blade, for marking square across a board.

1819. Silas Hawes of Vermont patents a one-piece steel framing square. Its stamped tables let a carpenter lay out rafters, braces and stair stringers without a calculator.

The speed square. 1925: Albert Swanson's triangle for marking cuts and rafter angles fast.

Today. Digital angle finders, laser squares, and the total station on a tower floor, but still the 3-4-5 check on the slab.

Try it. Use only a tape and a pencil to prove a corner is square. Then prove it with a 6-8-10.

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