how can i find the perimeter of the shaded region? any formula for the arc?

Question

anonymous · Answer

attachment

anonymous · Answer

This is very similar to the last question you asked. Where do you get stuck?

anonymous · Answer

formulas.. :|

anonymous · Answer

i'm confused if all forulas are same or not

anonymous · Answer

about the arcs

anonymous · Answer

I hope now you remember the formula for the perimeter of the circle

anonymous · Answer

make use of symmetry..it's helpful

anonymous · Answer

yep, pi(diameter)

anonymous · Answer

Yep that is right. 
What fraction of the circle is the arc you have here?

anonymous · Answer

1/4

anonymous · Answer

The other 2 sides are just str8 lines

anonymous · Answer

yep.. which is equal to 20

anonymous · Answer

Can you find the solution now? You have written all the necessary information down already

anonymous · Answer

pi(diameter) is correct for the circle but get used to 2pi(radius), that is a more common notation

anonymous · Answer

should i use the formul.. l+ 2(pi)(r)(theta/360)?

anonymous · Answer

i mean l= 2(pi)(r)(theta/360)?

anonymous · Answer

You do not need that. Just forget the above 2 lines.

anonymous · Answer

You need the perimeter of the circle: 2pi(radius) and the fraction 1/4

anonymous · Answer

oh, just that? to get the arc length?

anonymous · Answer

yep

anonymous · Answer

That arc length has 1/4 of the perimeter of a full circle

anonymous · Answer

my answer is.. 35.71.

anonymous · Answer

thank you so much:)

anonymous · Answer

Yep that is it