geometry

3. the horizontal reference line in a two-dimensional Cartesian coordinate system, running left-to-right, used with the vertical y-axis to define the position of any point on a graph using ordered pairs (x, y)
4. a triangle with at least two sides of equal length
5. a concept of endlessness, boundlessness, or something larger than any finite measure, not a specific number, but a state of going on forever, like a line that extends in both directions without end, or space without limits, signifying endless potential or extension
6. an angle that measures greater than 90 degrees (a right angle) but less than 180 degrees (a straight angle), appearing "wider" or "blunter" than a perfect corner, like the angle of a door open more than halfway
8. an angle that measures exactly 90 degrees (\(90^{\circ }\)), forming a perfect "L" shape or a quarter turn, often indicated by a small square symbol at its vertex where two lines meet perpendicularly
13. a special relationship (or rule) that assigns exactly one output to each input
14. the exact center point of a line segment, dividing it into two perfectly equal (congruent) parts, and is equidistant from both endpoints
15. the vertical line on a Cartesian coordinate plane, perpendicular to the horizontal x-axis, used to measure the vertical position (up/down) of points, representing the y-coordinate, with positive values going up and negative values going down from the origin (0,0)

1. an equation with one variable that requires two inverse operations (addition/subtraction, then multiplication/division) to isolate the variable and find its value, typically in the form of
2. the central reference point in a coordinate system, usually where the axes (x, y, and sometimes z) intersect, marked as (0, 0, 0), serving as the "home base" from which all other points are measured and located by their coordinates
7. identical in both shape and size, allowing one figure to be perfectly superimposed onto the other through translations, rotations, or reflections
9. the measure of a line's steepness and direction, defined as the ratio of the vertical change (rise) to the horizontal change (run) between any two points on the line
10. any angle that measures greater than 0 degrees and less than 90 degrees
11. one where all sides are of equal length (congruent), and consequently, all its internal angles are also equal, with each angle in an equilateral triangle measuring 60 degrees
12. a triangle where all three sides have different lengths, and consequently, all three internal angles also have different measures