Year 9 Geometry

6. A transformation that turns a figure around a fixed point, called the center of rotation.
10. A polygon with all sides and angles equal.
12. Two angles whose measures add up to 180 degrees.
17. An angle measuring less than 90 degrees.
18. A triangle with no sides of equal length.
19. An angle measuring exactly 90 degrees.
23. A triangle with at least two sides of equal length.
24. A theorem stating that in a right-angled triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the other two sides.
25. A line that intersects two or more lines in a plane.
27. The non-adjacent angles formed when two lines intersect; they are always congruent.
28. Angles formed between adjacent sides of a polygon.
29. A triangle with all three sides of equal length.
30. The figure formed by two rays with a common endpoint, called the vertex.

1. To divide an angle or segment into two equal parts.
2. Angles in the same position in two different shapes that are related by a transformation, such as a translation or rotation.
3. Lines that are equidistant and never intersect.
4. An angle formed by the extension of one side of a polygon and an adjacent side.
5. Having the same size and shape; identical.
7. A polygon with four sides.
8. An angle measuring more than 90 degrees but less than 180 degrees.
9. Figures that have the same shape but may differ in size.
11. Two angles that share a common side and vertex but do not overlap.
13. The longest side of a right-angled triangle, opposite the right angle.
14. The distance from the center of a circle to any point on the circle.
15. The total length of the sides of a polygon.
16. Lines that intersect to form a 90-degree angle.
20. A closed plane figure formed by three or more line segments
21. The common endpoint of two or more rays or line segments.
22. A transformation that flips a figure over a line, creating a mirror image.
26. A transformation that moves every point of a figure the same distance in the same direction.