Convenient Ruler / Ruler

Do you still draw angles by means of more than one rulers?our ruler will help you get rid of this complex way because it mixes the straightedge and protractor perfectly and skillfully through an annulus,ensuring that the bottom of ruler keeps in the same level.Meanwhile,it simplifies the traditional steps of using some rulers to draw angles.what you need to do is just to move one of straightedges easily,and then the angles you want will be done in a faster and correcter way.