Geometry helps in our daily life of adults as if you're an architect, an engineer or an artist, shapes how to calculate them are of utmost importance.
But, what if you aren't?
Well, if you like to play pool (like me!), then you should know that every shot you make is a series of triangles and functions that determine the outcome of the shot you take.
If you're driving, it is essential to know the turning radius (circles) of your car - or you might crash into your neighbor's tree!
When you're trying to decorate your house, shouldn't know know the space your furniture will take up in terms of the space that you have? That's area of quadrilaterals and similar polygons you're talking about.
If you use a ladder, you need to place it at an exact angle so you don't fall.
If you're a guy, you need to have the theory of arches down to a "T"... otherwise, your urine will land outside of the toilet ;-)
Like these, there are many everyday examples of things that we do that involve geometry.