SOLUTION: I have gotten an answer on this before but I don't understand it. Questions: 1. Write answer in terms of "pi": Find the length of arc AB with the measure of the inscribed a

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Question 998520: I have gotten an answer on this before but I don't understand it.
Questions:

1. Write answer in terms of "pi": Find the length of arc AB with the measure of the inscribed angle = 40� and the radius being 20.
2. Write the answer in "pi": find the length of arc AB when the measure of the arc is 70� and the radius of the circle is 10.
I would like in depth explanation of this please.
Answer by MathLover1(20849) (Show Source):
You can put this solution on YOUR website!
given: and
We can use the arc length formula , with � and

arc-length
since � = in radians
we have

or, you can do it this way:
whole circumference of a circle is =
if angle = }� , it is of , then => then you have
=>

2.
given: the measure of the arc is � and the radius of the circle is
One measure of an arc is the angle formed by the arc at the center of the circle that it is a part of.Remembering that the arc measure is the measure of the central angle,we have

�