## Unit 3: GEOMETRY

## Constructing Polygons with a compass and or protractor

## Congruence Vs Similarity

In real life, we use the word "similar" to mean different things. The term is somewhat vague. In math, it has a special definition. See the picture below. In math, two figures are called **similar** if they are the **same shape, but different sizes**, such as the turtles in the lower half of the picture. It doesn't matter if they are rotated or not. Two figures are **congruent** if they are **exactly the same size and the same shape, **such as the turtles in the top half of the picture. Again, rotation doesn't matter at all.

https://www.youtube.com/watch?v=nPbJQcfEWB8