The wheel additionally allows the Tiruler to function as a 180-degree protractor, by showing the numerical value of angles that are being either drawn or measured. The folding action of the ruler ...

What you need: ruler, protractor, pencil and paper ... In this case use the lengths 8 cm, 4 cm and 5 cm. Set the compass width to 5 cm. Place the compass at the other end of the line and draw ...