The slide rule, pencil and magnifying glass are on the notebookThe slide rule, pencil and magnifying glass are on the notebook
Abstraction of triangles and angles in white red blue and purpleAbstraction of triangles and angles in white red blue and purple
Abstraction of dark green and blue with circles and linesAbstraction of dark green and blue with circles and lines
The intersection of different lines of black gray and orange colorsThe intersection of different lines of black gray and orange colors