options: Given a rectangle, parallelogram, trapezoid, or regular polygon, describe the rotations and reflections that carry it onto itself.

Given a geometric figure and a rotation, reflection, or translation, draw the transformed figure using, e.g., graph paper, tracing paper, or geometry software. Specify a sequence of transformations that will carry a given figure onto another.

Develop definitions of rotations, reflections, and translations in terms of angles, circles, perpendicular lines, parallel lines, and line segments.

Represent transformations in the plane using, e.g., transparencies and geometry software; describe transformations as functions that take points in the plane as inputs and give other points as outputs. Compare transformations that preserve distance and angle to those that do not (e.g., translation versus horizontal stretch).

Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.
problem_activity: Problem 1
Find all the angle measures that equal 127° and all the angle measures that are supplementary to 127°.
[IMG]
Problem 2
In the figure,
$${\overline{AB} \parallel \overline{CD}}$$
and
$${\overline{EF} \parallel \overline{GH}}$$
. Prove that
$${\angle AFE \cong \angle DKH}$$
.
[IMG]


correct_option_index: 4