## stupidinmath one year ago how can i find the perimeter of the shaded region? any formula for the arc?

1. stupidinmath

2. Andras

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

3. stupidinmath

formulas.. :|

4. stupidinmath

i'm confused if all forulas are same or not

5. stupidinmath

6. Andras

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

7. Abhishek619

8. stupidinmath

yep, pi(diameter)

9. Andras

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

10. stupidinmath

1/4

11. Andras

The other 2 sides are just str8 lines

12. stupidinmath

yep.. which is equal to 20

13. Andras

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

14. Andras

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

15. stupidinmath

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

16. stupidinmath

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

17. Andras

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

18. Andras

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

19. stupidinmath

oh, just that? to get the arc length?

20. Andras

yep

21. Andras

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

22. stupidinmath

23. stupidinmath

thank you so much:)

24. Andras

Yep that is it