Convert the complex number into its polar representation:
-4

-4i is a complex number, and complex number can be seen as vector too.
Polar form of a number, on the other hand is representation of the number in polar coordinates. So, converting complex number into its polar representation is writing the complex number in terms of a distance from the origin and a direction (or angle) from the positive horizontal axis.
The polar form of complex number can be written as: 
x+yj=r(cos(alfa)+sin(alfa)), where r is the absolute value (the modulus) of the complex number and alfa is the argument of the complex number.
r=sqrt(x^2+y^2)=sqrt(4^2+0)=sqrt(16)=4
alfa=tanges^(-1)(0/4)=tanges(0)=0
-4i=4*(1+0)=4

  henry proves that the british are trying to subjugate or control the colonies by force by indicating that the fleets of ships were preparing to attack. he believes that if the colonies back down from a war, they might become prisoner of the british rulers.

I’m sorry, but this question confuses me. could you clear it up a bit? i’d love to ! : )