standard_description: Use a pair of perpendicular number lines, called axes, to define a coordinate system, with the intersection of the lines (the origin) arranged to coincide with the 0 on each line and a given point in the plane located by using an ordered pair of numbers, called its coordinates. Understand that the first number indicates how far to travel from the origin in the direction of one axis, and the second number indicates how far to travel in the direction of the second axis, with the convention that the names of the two axes and the coordinates correspond (e.g., x-axis and x-coordinate, y-axis and y-coordinate).
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]


aligns: no