A multipurpose drawing tool is provided. One embodiment of the tool that is advantageous for drawing circles one-handedly includes a protractor portion and an elongated radius arm portion. The protractor portion includes an aperture, and a securing member is rotatably mounted in the aperture. The securing member may be a transparent or translucent suction cup for releasably attaching the tool to a drawing surface such as a vertically-oriented dry-erase or chalk board. Alternatively, the securing member may be a transparent or translucent magnet or a conventional magnet configured with a generally annular or toroidal shape. In another embodiment, an improved protractor is provided that includes a straightedge portion, a semicircular portion, a pivot arm and a suction cup or magnet securing member that pivotally secures an end of the arm to a central portion of the straightedge portion.