The general rotation transformation is to draw a 90-degree rotation. In the case of grid, first find the point to be rotated (such as point A), and then find the center of rotation (such as point O). At this time, look at the rectangle of the two vertices where point A and point O are located, and see clearly its horizontal length and vertical length (if it is one grid in the horizontal direction and three grids in the vertical direction, it is recorded as 1×3). Then find a rectangle with the vertex o, which is at right angles to the rectangle just now (the rectangle should be three squares horizontally and one square vertically, that is, 3× 1), look clockwise to the right and counterclockwise to the left. Then, according to the shape of the rectangle just now (that is, the positional relationship between point A and point O), find out point A' in the newly found rectangle.
2. Connect the wires according to the connection method in the original drawing.
After drawing all the corresponding points, connect them in order. If point A is originally connected with point B, then among the good points in China, point A' should be connected with point B'.
Don't forget the necessary words (for example, △A'B'C' is what you want).
If there is no grid, measure the length with compasses, trigonometry and protractor, draw an arc or circle with the rotation center as the center and the distance from each point to the rotation center as the radius, then measure the angle to be rotated with trigonometry or protractor, and finally connect the lines.