Spherical trigonometry

Spherical trigonometry is a kind of math we use to figure out the angles of things when they're on a round shape, like the Earth. It's different from regular trigonometry because a sphere is not flat, like a piece of paper. On a sphere, angles can be more than just 180 degrees, since the shape curves around in three dimensions, like a ball. In spherical trigonometry, we use circles to measure angles and use special equations to figure out how far apart two places on the sphere are. It's also used to map the surface of the Earth, so that we can see where things like countries and cities are.