0 a flat piece of metal or plastic in the shape of a triangle with one angle of 90°, used for drawing angles -- 三角板
If you take this to its logical conclusion, the entire map would have to be redrawn, with a set square and ruler.
He learned how to use a set square, ruler, and other tools.
More commonly the set square bears the markings of a ruler and a half circle protractor.
Different objects such as a book, a set square, two stepping stools and an egg float around the main figure.
The most simple form of set square is a triangular piece of transparent plastic (or formerly of polished wood) with the centre removed.
Other tools used are circle compass, ruler, and set square.
Less commonly found is the adjustable set square.
This instrument was basically a carpenter's set square with a graduated arc and plumb-bob placed in the muzzle to measure an elevation.
