It will be easier to explain how to solve this question in a square. If you rotate 4-sided square from the centre, you need to rotate it 90 degrees. The formula for this would be: 360 ° /the side count. In a square, it would be 360° /4= 90°.
In 18-sided polygon, the calculation would be: 360°/ 18 side= 20°
The triangle will be rotated with the rule of (x,y) → (-y,x). The image will be congruent to the pre-image, the side lengths will be the same and the angles too.
Answer:
0.9
Step-by-step explanation:
