Geometry is the part of mathematics that deals with calculating the distance around a circle, the angles that make up a triangle, or the amount of room inside a cube. If it involves measuring space, it’s probably geometry.
The Greek roots of geometry literally mean “to measure earth,” and over 5000 years ago farmers started using geometry to figure out how much land they owned. You study geometry in school, and you use it all the time, like calculating the best angle to cut a piece of wood for a birdhouse, or when playing a game of pool. Astronomers use geometry to measure planets millions of miles away—much easier than finding a ruler that big.
