#### Answer

A-C = (38.85 units, 51.66 units)
R = 64.64; 53.06$^o$

#### Work Step by Step

Use equations 3.3a and 3.3b to find the x and y components. Vector C points at 270 degrees from the positive x-axis.
Vector A = (38.85, 20.66)
Vector C = (0, -31)
Take the difference by subtracting corresponding components.
A-C = (38.85 units, 51.66 units)
$R = \sqrt {(38.85)^2+(51.66)^2} = 64.64$
$\theta=tan^{-1}(\frac{51.66}{38.85}) = 53.06^o$