Span
That is a great word to add to our toolkit!
If your bar compass has a span of 20cm, that means it can reach far enough to draw a circle that is 40cm wide (since the span is the radius).
In Math, we use span to talk about the width of shapes, and in Technology, engineers measure the "span" of a bridge to make sure it’s strong enough to stretch across a river without falling.
It’s all about measuring that start-to-finish distance!Since your compass can span 20cm, do you want to see how to use Math to figure out the area of the giant circle it can draw?