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 Type-90 The Type-90, also known as the MZD-2, is a Chinese submunition used in the 122 mm Type-81 cluster rocket. It is made by Norinco. Type-81 rockets with Type-90 submunitions were used by Hezbollah against Israel in the 2006 Lebanon War, and they have been used in the Syrian Civil War as bombs dropped by weaponized Hezbollah quadcopters. Each Type-90 resembles a small cylindrical bell with a ribbon at one end. A plastic band full of 3mm steel spheres wraps horizontally around the middle of the cylinder. Inside is an armor-piercing shaped charge. Each Type-81 rocket contains 39 Type-90 submunitions.