Geometry is an aspect of graphics, which does not involve the relationship between quantities (such as congruence of triangles).

Algebra is about quantitative relations, algebraic calculation and solving equations, all of which belong to algebra.

But algebra and geometry are also complementary.

For example, Pythagoras theorem, which is not only based on geometry, but also shows the algebraic relationship between three sides (a? +b？ =c？ )