algebra precalculus - Using unit circle to explain $\cos(0) = 1

We have been taught $\cos(0) = 1$ and $\sin(90) = 1$. But, how do I visualize these angles on the unit circle?

3.4 Sine and cosine function graphs, AP Precalculus Math, AP Precalculus (BETA)

5.2: Unit Circle - Sine and Cosine Functions - Mathematics LibreTexts

Solved Use the unit circle below and the appropriate formula

5.2: Unit Circle - Sine and Cosine Functions - Mathematics LibreTexts

The Unit Circle - Precalculus Tips

Unit circle (video), Trigonometry

Unit Circle Quadrants, Converting, Solving & Memorizing - Lesson

Unit Circle

Math Tricks To Remember The Unit Circle (video lessons, examples and solutions)

PRECALCULUS: The Unit Circle

Understanding the unit circle

cos0, SAVE 56%

Trigonometry - Easy Way To Memorize The Unit Circle