Forward kinematics of RRR manipulator. RRR manipulator is a model of robot which contains three rotary joints. In first step coordinates systems are assigned to manipulator joints. Assigning of coordinates systems is made via Denavit-Hartenberg notation. At second step table with Denavit-Hartenberg's parameters is written. Robot has three joints then number of coordinates systems is equal to three. General form of transformation matrix is used. Transformation matrixes between consecutive coordinates systems are written. As a result three transformation matrixes are obtained. Transformation matrix which describes any position from last coordinates system in base coordinates system, is obtained by multiplying transformation matrixes between consecutive coordinates systems.