Question

the adjoining figure when rotated through 120*,240*,360*will fill exactly onto itself each time .how many angles in symmetry order clock wise and anticlockwise which angle are there​

Answer 1

Answer:

When the hands of a clock go round, we could say that they rotate. The hands of a clock rotate in only one direction, about a fixed point, the centre of the clock-face. Rotation, like movement of the hands of a clock, is called a clockwise rotation; otherwise it is said to be anticlockwise. If you spin the wheel of a bicycle, it rotates. It can rotate in either way: both clockwise and anticlockwise.

When an object rotates, its shape and size do not change. The rotation turns an object about a fixed point. This fixed point is the centre of rotation.

The angle of turning during rotation is called the angle of rotation. A full turn, you know, means a rotation of 360°. A half-turn means rotation by 180°; a quarter-turn is rotation by 90°.

When it is 12 O’clock, the hands of a clock are together. By 3 O’clock, the minute hand would have made three complete turns; but the hour hand would have made only a quarter-turn.

The Paper windmill in the picture looks symmetrical ; but you do not find any line of symmetry. No folding can help you to have coincident halves. However if you rotate it by 90° about the fixed point, the windmill will look exactly the same. We say the windmill has a rotational symmetry.