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The angle addition postulate helps us understand even more about geometry and angles. Using this postulate, we can solve all kinds of additional geometry problems. But what exactly is the angle addition postulate? Let's find out:

## The angle addition postulate defined

In the world of mathematics, a "postulate" is something we assume to be true. Postulates are like rules that we can apply to a range of different situations.

The angle addition postulate states that if we put a line between any angle and divide it into two separate angles, these two angles must add up to equal the measure of the first undivided angle.

## Visualizing the angle addition postulate

It helps to visualize how the angle addition postulate works:

As you can see, there are three angles here:

The first angle is formed by the sides A, O, and B.

The second angle is formed by the sides B, O, and C.

The third angle is formed by the sides A, O, and C.

The angle addition postulate tells us that if we add the first two angles together, it must equal the measure of the third angle.

In other words, the two smaller angles come together to make the third.

## Topics related to the Angle Addition Postulate

Angles

Alternate Interior Angles Theorem

## Flashcards covering the Angle Addition Postulate

Common Core: High School - Geometry Flashcards

## Practice tests covering the Angle Addition Postulate

Common Core: High School - Geometry Diagnostic Tests