Answer
$A=47.2m$
Work Step by Step
Use Pythagorean theorem to find the length of the vector, since the two component vectors are perpendicular. $$a^2+b^2=c^2$$ $$A_x^2+A_y^2=A^2$$ $$(-25.0m)^2+(40.0m)^2=A^2$$ $$A=\sqrt{(40.0m)^2+(-25.0m)^2}$$ $$A=47.2m$$
