how to draw an supplymentry angel of 40 degrees

The angles which are multiples of 15° for example 30°, 45°, 90°, 135° etc. can only be drawn with the help of compass.

The angles which are not multiples  of 15° for example, 10°, 40°, 67°, 140°, 160° etc. can easily be drawn with the help of protractor. 

Moreover, the process of constructing any angle with the help of protractor is explained with the help of an example in the below mentioned link.

https://www.meritnation.com/ask-answer/question/draw-an-angle-of-108-degree/constructions/4096388