1. Point An exact position or location in a given plane.
Is represented by a dot and named with a capital letter.
Point A or Point B

2. Line
The set of points between points in a plane and the infinite number of points that continue beyond the points.
Written as Q P

3. Line Segment
A line with two endpoints.
Written as

4. Distance along a line
The linear distance between two points on a given line.

5. Parallel Line
Lines in a plane that either do not share any points and never intersect, or share all points.
Written as

6. Perpendicular Line Two lines that intersect at a right angle (90°).
Written as

7. Ray
A line that has one endpoint and continues on forever in the opposite direction. B C D E A

8. Angle
A shape, formed by two lines or rays diverging from a common point (the vertex).
The angle is

9. Right Angle
An angle that measures 90°.

10. Acute Angle
An angle measuring less than 90° but greater than 0°.

11. Obtuse Angle
An angle measuring greater than 90° but less than 180°.

12. Straight Angle
An angle measuring exactly 180°.

13. Adjacent Angles Two angles that share a common vertex and side.
SIDE BY SIDE

14. Linear Pair
Two adjacent angles that form a straight line. 1 2

15. Vertical Angles
Two angles directly across from each other. They share a common vertex. E & G and H & F are vertical anlges. h f e g

16. Supplementary Angles
Two angles that add up to 180°. 1 2

17. Complementary Angles
Two angles that add up to 90 degrees. 1 2

18. Circle
The set of all points in a plane equidistant from a certain point called the center.

19. One-to-One
A relationship wherein each point in a set of points is mapped to exactly one other point.

20. Pre-image
The original figure before undergoing a transformation.

21. Image
The new, resulting figure after a transformation

22. Isometry
A transformation in which the preimage and image are congruent preserving length and angles measure and distance between lines

23. Every segment is congruent to its image.
Transformations are called RIGID if every image is congruent to its preimage.
Rigid transformations can also be referred to as an ISOMETRY.
Every segment is congruent to its image.

24. Congruent
Figures are congruent if they have the same shape, size, lines, and angles.

25. Similar Triangles
Triangles are similar if they have the same shape but have different sizes.

26. To divide into two congruent parts.L J
BISECT K M

27. Line of Symmetry
the imaginary line where you could fold the image and have both halves match exactly

28. Find the value of each variable, given that the transformation is an isometry.

29. Which of the following are rigid transformations? (Isometry)