A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

The Ruffs are planning to buy an above-ground swimming pool shaped as a regular octagon. The radius of the octagon is 9 feet. To the nearest tenth, find the area of the surface of the water in the pool. Possible answers: A) 458.2 ft2 B) 553.1 ft2 C) 94.8 ft2 D) 229.1 ft2 Thanks!

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    A=r^2*2.828

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So A=(9)^2*2.828=229.068

  3. dumbcow
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    octagon can be split into 8 equal isosceles triangles Area of octagon will be 8X area of each triangle 360/8 = 45 top angle opposite of base is 45 degrees 180(8-2) = 1080, this is sum of interior angles 1080/8 = 135 135/2 = 67.5 bottom 2 angles opposite of radii are 67.5 degrees to find area of triangle we need base length(x) and height(h) use trig ratios h = 9sin(67.5) x = 18cos(67.5) Area = 8*(1/2)*(9sin(67.5))*(18cos(67.5)) Area = 648*sin(67.5)*cos(67.5) Area = 229.1

  4. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.