DEMONSTRATION PROTRACTOR Russian patent published in 2019 - IPC G09B23/04 

FIELD: personal usage items.

SUBSTANCE: semicircular demonstration protractor allows pupils to perceive geometry material more easily, since they work with material rays fixed movably in the center of the protractor to build angles. Working with such a protractor model, the students not only see that each beam emanates from the center of the protractor, but relative to the center of the protractor, along the angular scale, the rays perform movement. Movement of the rays is controlled by an arc, fixed at the edges to a rectilinear scale, behind the protractor. Movement of any beam stops at a value with a mark of 0° used goniometric scale.

EFFECT: use of mobile rays allows to visually show: acute angles, right angle, obtuse angles, unfolded angle and the relationship between the unfolded and right angle, otherwise approach the solution of complex, abstract geometric problems.

1 cl, 2 dwg