First of all I liked your question. Actually it gave me an idea of adding real life applications of mathematical concepts to my site! Thank you!
Q: What is the practical application of congruence nowadays?
Two objects are congruent if they have the same dimensions and shape. Clearly, you can think of it as meaning ‘equal’.
When any object is kept in front of the mirror, that mirror image is congruent to the real image.
When two objects or shapes are said to congruent then all corresponding angles and sides also congruent.
Real life examples are,
- cigarettes in a packet are congruent to one another.
- Giant wheels or ferris wheels.
- Pages of one books are congruent to one another and etc