Geometric Representations of Complex Numbers Practice Test

A point $(a,b)$ on the complex plane represents the complex number $a+bi$.

Which complex number corresponds to the point $(-2,-7)$?

A force is modeled as the complex number $F=3+4i$, where $3$ is the horizontal component and $4$ is the vertical component. What is the magnitude of the force (the modulus $|F|$)?​