Geometry Foundations Exam Part One — Study 1/4

Module 01 — Geometry Foundations

The big idea Review the geometry building blocks and learn how to tell definitions, postulates, and theorems apart.

Your first study session

Today, focus only on the basic figures and the kinds of statements used in geometry. Say each definition aloud before moving on.

When you finish the three-question check, continue to Study for Geometry Test — 2/4.

A geometry diagram beside proof statements
First name the figure or statement type; then explain why it fits.

Point, line, and plane

Point, line, and plane are undefined terms. A point names a location and has no dimension. A line has one dimension and continues forever in both directions. A plane is flat, has two dimensions, and continues forever.

A segment is part of a line with two endpoints. A ray has one endpoint and continues forever in one direction.

A segment with endpoints A and B
Two endpoints make a segment.
A ray beginning at A and passing through B
One endpoint and one continuing direction make a ray.

Definition, postulate, or theorem?

A definition tells exactly what a word means. A postulate is accepted as true without proof. A theorem is proven using definitions, postulates, and earlier results.

Example: “Through any two points, there is exactly one line” is a postulate. “Vertical angles are congruent” is a theorem.

Quick clue: meaning = definition; accepted starting fact = postulate; proven result = theorem.
Two intersecting lines forming four angles
The Vertical Angles Theorem is a proven result.

Check Part 1

Answer all three without notes. If one is wrong, return to the card that explains it and try again.

1 / 3 0 correct