Angle of rotation Angle of rotation In mathematics, the angle of rotation is a measurement of the amount, namely the angle, that a figure is rotated about a fixed point, often the center of a circle. A clockwise rotation is considered a negative rotation, so that, for instance, a rotation of 310° (counterclockwise) can also be called a rotation of –50° (since , a full rotation (turn)). A counterclockwise rotation of more than one complete turn is normally measured modulo 360°, meaning that 360° is subtracted off as many times as possible to leave a non-negative measurement less than 360°. For example, the
Type 90 Kyū-maru to the left of the main gun. The profile of the Type 90 is similar to the German Leopard 2A4 and it uses modular ceramic and steel composite armor, common in contemporary tank designs. The adoption of modular composite armor design facilitates the upgrading and exchange of the armor, and its frontal turret armor is rated at 380mm of effective thickness against kinetic energy penetrators, while the upper frontal hull armor is rated at 320mm of effective thickness against kinetic penetrators. The Type 90 is smaller than most main battle tanks with a height of , a width of ,