## RWA Triangle Inequality Theorem

### Topic

History of Math

### Vocabulary

- Triangle Inequality Theorem

### Student Exploration

#### How long ago was the triangle inequality theorem first written down?

Watch to learn more:

Read more here: http://www.historyforkids.org/learn/greeks/science/math/euclid.htm

A fragment of Euclid's elements found at Oxyrhynchus, which is dated to circa 100 AD. The diagram accompanies Proposition 5 of Book II of the *Elements*. http://en.wikipedia.org/wiki/Euclid's_Elements

### Extension Investigation

Solve problems using the Triangle Inequality Theorem

Triangle Inequality Theorem

http://www.mathopenref.com/triangleinequality.html

#### Layering (optional)

Triangle Inequality Theorem

Theorem

http://www.youtube.com/watch?v=i9x4cTJ18is&feature=related