How do we find the area of a octagon (side lengths are not correct)

Поділитися
Вставка
  • Опубліковано 7 сер 2024
  • 👉 Learn how to find the area and perimeter of polygons. A polygon is a closed shape with 3 or more sides. The area of a shape is the measure of the portion enclosed by the shape while the perimeter of a shape is the measure of the outline enclosing the shape.
    To find the area of a polygon, we use the formula for finding the area of the polygon or we can break the polygon into smaller triangles and calculate the area of the triangles and then sum up the areas of the triangles. To find the perimeter of a polygon we obtain the measures of the outline of the polygon.
    👏SUBSCRIBE to my channel here: ua-cam.com/users/mrbrianm...
    ❤️Support my channel by becoming a member: / @brianmclogan
    🙋‍♂️Have questions? Ask here: forms.gle/dfR9HbCu6qpWbJdo7
    🎉Follow the Community: / mrbrianmclogan
    Organized Videos:
    ✅Area and Perimeter
    • Area and Perimeter
    ✅Area and Perimeter of Composite Figures
    • Area and Perimeter of ...
    ✅Area and Perimeter of a Rectangle
    • Area and Perimeter of ...
    ✅Area and Perimeter of a Polygon
    • Area and Perimeter of ...
    ✅Area and Perimeter of a Triangle
    • Area and Perimeter of ...
    ✅Area and Perimeter of a Trapezoid
    • Area and Perimeter of ...
    ✅Area and Circumference of a Circle
    • Area and Circumference...
    ✅Area and Perimeter of a Parallelogram
    • Area and Perimeter of ...
    🗂️ Organized playlists by classes here: / mrbrianmclogan
    🌐 My Website - www.freemathvideos.com
    🎯Survive Math Class Checklist: Ten Steps to a Better Year: www.brianmclogan.com/email-ca...
    Connect with me:
    ⚡️Facebook - / freemathvideos
    ⚡️Instagram - / brianmclogan
    ⚡️Twitter - / mrbrianmclogan
    ⚡️Linkedin - / brian-mclogan-16b43623
    👨‍🏫 Current Courses on Udemy: www.udemy.com/user/brianmclog...
    👨‍👩‍👧‍👧 About Me: I make short, to-the-point online math tutorials. I struggled with math growing up and have been able to use those experiences to help students improve in math through practical applications and tips. Find more here: www.freemathvideos.com/about-me/
    #areaandperimeter #brianmclogan

КОМЕНТАРІ • 49

  • @LarsHHoog
    @LarsHHoog 6 років тому +48

    2715 views and nobody has commented that the information is totally incorrect.
    If the sides of a regular octagon is 15 then the distance from the center to the mid point on the edges isn't 20.
    Your calculation of a=20 is therefore false and the actual area of a regular octagon with side 15 is ~1086.4

    • @brianmclogan
      @brianmclogan  6 років тому +19

      yes, c'mon people! I think I made this problem up a way long time ago which as you mentioned does not work. Should have been more careful before deciding to do that. Thank you so much for point it out. Much appreciated

    • @csm5040
      @csm5040 6 років тому +2

      Lars Höög.
      Yep, I just realized when I saw it.
      The relationships of the side and the apothem of an octagon is a constant, 0.8 or 4/5.
      That means that if we have an octagon whose sides measures 15, its apothem must be 18.75.
      And if the apothem is 20, the side must be 16.

    • @csm5040
      @csm5040 6 років тому +4

      Anyways, I appreciate the fact that he is trying to teach us.

    • @markzuckerberg6054
      @markzuckerberg6054 6 років тому +18

      we are here cause we know nothin bout octagon how can we be able to spot the mistakes?

    • @bobbib3246
      @bobbib3246 4 роки тому

      @sebastian hale The video still provides correct information which is how to find the area of the octagon when you are given the apothem. So there was nothing wrong with his explanation of how to get the answer 🤷‍♀️

  • @noahcastillo7120
    @noahcastillo7120 3 роки тому +18

    I know this video was put out 6 years ago, but I had to say something. This video has just saved my freshman year. Thanks for your knowledge

    • @TheChessRobloxian
      @TheChessRobloxian 4 місяці тому +1

      9 years now and my math assignment is a breeze cause of him.

  • @comfymoon382
    @comfymoon382 8 років тому +5

    I was so confused on my hw and I saw this vid thank u so much helped a lot

    • @brianmclogan
      @brianmclogan  8 років тому

      +Comfy Moon sweet! happy to help!

  • @josep.garcia963
    @josep.garcia963 8 років тому +6

    Your explanation was really easy thank you.😀😋

    • @brianmclogan
      @brianmclogan  8 років тому

      +jose garcia you are very welcome! happy to helped

  • @GibbyGuyGo
    @GibbyGuyGo 9 років тому +7

    HELPED SO MUCH THANKS

    • @brianmclogan
      @brianmclogan  9 років тому

      GibbyGuyGo you are very welcome! happy to help!

  • @tomcowley7160
    @tomcowley7160 2 роки тому +2

    How do you get the length of each side if you only have the diameter

    • @TheChessRobloxian
      @TheChessRobloxian 4 місяці тому +1

      For my math assignment we have to measure the sides with a ruler.

  • @carterbailey8235
    @carterbailey8235 7 років тому +3

    Thanks so much I missed a class because of some family matters and this helped a lot

  • @melodysanchez4508
    @melodysanchez4508 2 роки тому

    Thank You!

  • @ygmsniper
    @ygmsniper 3 роки тому

    how can you get the actual value of the apothem of any polygons? like in the pentagon, hexagon or even decagon?

  • @harryxiro
    @harryxiro 3 роки тому +1

    You could work out the area with only the side length. Here's a formula where n equals the side length. A = (n (root 2) + n)^2 - n^2.
    n(root 2) + n = height of an octagon, thus the area of an octagon equals h^2 - n^2 (h is height and n is side length)

  • @sheylabraddock721
    @sheylabraddock721 5 років тому +2

    How would you solve it if the apothem isn't given?

    • @kenfarmer1139
      @kenfarmer1139 4 роки тому +1

      You could work out what the angles are, then use sine, cos or tan to get length of apothem.

  • @MissingMarss
    @MissingMarss 4 роки тому +2

    YOURE AMAZINGGGG YOU SAVED MY HM GRADE

  • @chessmathtricks4025
    @chessmathtricks4025 11 місяців тому

    1200 exactly

  • @funera1party57
    @funera1party57 3 роки тому

    what if I don't know the apothem?

  • @thirteenpixelz7365
    @thirteenpixelz7365 7 років тому +4

    Great

  • @galacticgiselle9327
    @galacticgiselle9327 3 роки тому

    I wish I had this type of brains

  • @rosemariiegrace
    @rosemariiegrace 3 роки тому

    how do you find the apothem of a regular octagon?

  • @Jack-lt2jd
    @Jack-lt2jd 7 років тому +1

    Waddup Brian

  • @asparrow876
    @asparrow876 4 роки тому +4

    A=1/2 ap
    A=1/2 (20).(15)(8)
    A=1/2 (20) (120)
    A=1/2 (2400)
    A=2400/2
    A=1200🤔
    am i correct?😅

  • @sofiabrooke8654
    @sofiabrooke8654 3 роки тому

    we stan

  • @arya6833
    @arya6833 3 роки тому

    All sides=10
    Area of a octagon=?

  • @mailaloomy4219
    @mailaloomy4219 6 років тому +2

    My works too. Used woodprix handbooks and build it with no problems.

  • @padmeamidala437
    @padmeamidala437 8 років тому +1

    Thank you soooo much this really helped me.... Btw I'm in 6th Grade

    • @brianmclogan
      @brianmclogan  8 років тому

      +Padme Amidala Robles awesome! keep up the hard work, you are off to a great start!

  • @montefrancis369
    @montefrancis369 6 років тому +6

    Its wrong

    • @brianmclogan
      @brianmclogan  6 років тому

      yes the apothem is incorrect and noted in the comments

  • @lifeizredz4681
    @lifeizredz4681 4 роки тому

    Incorrect.

  • @briceleroy
    @briceleroy 4 місяці тому

    I don't think this is a good idea to keep this video up, it creates a lot of confusion