Match each complex number with its equivalent expression -1 , 1 ,i,,-I

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like:

question

given the diagram below, what is md?

the sum of the interior angles is 360°

take away from 360 the sum of the knows angles and you will have the angle d.

360 - 108 - 108 - 72 = 72°