The Columbian Exchange, Spanish Exploration, and Conquest: An AP® US History Study Guide
Introduction The Columbian Exchange and Spanish exploration shaped the world as it is known today. … Read more
The Albert Team
European Exploration in the Americas: AP® US History Review
Introduction The story of European Exploration in the Americas marks a major turning point in … Read more
Native American Societies Before European Contact
Introduction Before Europeans arrived, Native American societies thrived across North America for thousands of years. … Read more
Contextualization in Period 1: AP® US History Review
Contextualizing Period 1 (1491–1607) — A Study Guide for AP® US History Students Understanding Period … Read more
Circle Power: A Study Guide to Properties and Circle Theorems
Introduction Circles are SAT® Math all-stars. They slip into area questions, hide in tricky angle … Read more
Unit Circle, Degrees, and Radians: A SAT® Math Study Guide
Circle questions pop up all over the SAT® Math section. However, many students lose points … Read more
Equation and Graph of a Circle: An SAT® Math Study Guide
Circles show up often on the SAT® Math Test. They may appear alone, mixed with … Read more
Pythagorean Theorem for SAT® Math: Right-Triangle Tools, Shortcuts, and Step-by-Step Examples
Right triangles appear on almost every SAT® Math section. Therefore, knowing their properties saves time … Read more
Right Triangle Trigonometry & Special Right Triangles: A Guide
Introduction Right triangles show up on nearly every SAT® Math exam. When a problem involves … Read more
Triangle Proofs, Theorems, and Scale Factors: Your SAT® Math Study Guide
Geometry reasoning shows up on almost every SAT® Math section. Yet, many students find formal … Read more