Need help, will medal

Question

zarkam21 · Answer

attachment

mjdennis · Answer

I have seen you get help on a zillion of these.  I think you can go through the steps on this one, too.
Let's start in Part I - which of the two options do you think is the correct answer?

zarkam21 · Answer

Half

mjdennis · Answer

Good.
You know measure of angle ABC, so what is the measure of arc AC (the smaller one)?

zarkam21 · Answer

20

zarkam21 · Answer

For part II, I got 20 and for part III I would just add right

mjdennis · Answer

Nope.  You need to think in full sentences.  

When you answered "half", you basically told me "the _angle_ is _half_ the arc".  If you put "40° " in place of "the angle", we get
"40° is _half_ the arc."

So, what is the arc?

zarkam21 · Answer

oh 80?

mjdennis · Answer

Good.
Finally, Part III:  You got 80° for the arc AC.  You need the other part of the circle, arc ABC  So you need to know how far around a full circle, which is the same for any circle?

Not sure what "just add" meant, so no comment on that.

zarkam21 · Answer

So you need to know the degrees for any circle

mjdennis · Answer

Right.  Always 360°.  Any circle.

mjdennis · Answer

So if mAC = 80°, and mAC+mABC=360°, what is mABC ?

mjdennis · Answer

You didn't keep your commitment to give a medal.