The Y Ruler’s array of features extends beyond those of a traditional ruler. It includes two straight edges, a compass/corner rounder, a set square, and a protractor with a scale that reads in 1 ...

STEP 1: Using a pencil and ruler, draw a horizontal line. Set the compass to the width of the line. Place the compass at either end of the line and draw two arcs that cross in the middle.

In this triangle two angles, 50⁰ and 40⁰, and the side between them, 9 cm, are known. This is an ASA (Angle, Side, Angle) construction, which can be constructed using a protractor and a ruler.