First we will define both courses:
Algebra: is the name that identifies a branch of Mathematics that uses numbers, letters and signs to be able to refer to multiple arithmetic operations.
Geometry: Part of the mathematics that studies the extension, the way of measuring it, the relationships between points, lines, angles, planes and figures, and the way they are measured.
For the study of engineering requires extensive knowledge in different fields of mathematics. However, as the engineer must handle an endless number of equations, more knowledge in algebra is more important.
Answer:Algebra.