Mammoth Memory

Rotation - think pencil compass

On any mathematical rotation think

Rotation think pencil compass, using curves and circles makes working out rotations so much easier

Rotation - Pencil compass

And with any rotation a pencil compass would need a centre, the direction to move (clockwise or anticlockwise) and the number of degrees to move.

Centre the compass on the intersection of x and y axis and rotate clockwise or anticlockwise with the measurement of the question

Centre, Clock and anticlockwise and number of degrees


Below is an example of a triangle (`W`). Rotate this triangle 90° clockwise with the centre of rotation being at the origin of the graph (0,0).

Rotate this triangle using a compass with the centre of the compass on xy

Rotate point "`a`" first.

Rotate corner A using a compass

Now rotate point "`b`"

Rotate corner B using a compass

Finally rotate point "`c`"

Rotate corner C using a compass

Draw the new shape by connecting the dots

Triangle `W` rotated 90° clockwise from (0,0)`=W^1`.



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