Unit 1 Vocabulary Angle An angle measuring less

Unit 1 Vocabulary

Angle • An angle measuring less than 90° but greater than 0° The angle is

Circle • The set of points on a plane at a certain distance, or radius, from a single point, the center.

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

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

Line Segment A line with two endpoints. Written as

Point An exact position or location in a given plane. Point A or Point B

Line The set of points between points P and Q in a plane; extends in both directions without end (infinitely). Written as

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

Right Angle An angle that measures 90°.

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

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

Pre-image The original figure before undergoing a transformation.

Image The new, resulting figure after a transformation

Isometry A transformation in which the preimage and image are congruent.

Clockwise In a curve corresponding in direction o the typical forward movement of the hands of a clock.

Counter Clockwise In the opposite direction to the way in which the hands of a clock move around.

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.

Which of the following are rigid transformations? (Isometry)

Isometries not only preserve lengths, but they preserve angle measures parallel lines, and betweenness of points

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

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

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

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