Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

how to work out the area of a circle

Announcements Posted on
Applying to Uni? Let Universities come to you. Click here to get your perfect place 20-10-2014
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    i need to know how to work out the area of a circle by using the diameter
    so if the diameter was 12.3 what would be the answer and how would you work it out?
    • 1 follower
    Offline

    ReputationRep:
    divide diameter by two to get the radius.

    area = pi x radius squared
    • 11 followers
    Offline

    ReputationRep:
    Have you learnt any formulas for finding the area of a circle?
    • 8 followers
    Offline

    ReputationRep:
    A = \pi r^2
    d = 2r
    \Rightarrow A = \frac{1}{4}\pi d^2
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    right so just let me check ive done this question right and if i have im sorted
    the question was find the area of a circle by using diameter=14.8cm
    so i do 14.8 divided by 2=7.4 pie time 7.4 squared=172.3

    is this correct?
    • 63 followers
    Offline

    ReputationRep:
    3.14*6.15 squared = 118.76 (2dp)

    I think
    • 0 followers
    Offline

    ReputationRep:
    It's 172.03, but I'm guessing that was just a typing error.
    • 0 followers
    Offline

    ReputationRep:
    Right, this is a rhyme (!) which will mean u never 4get this formulae again!!!

    Tweedle dum and tweedle dee,
    round the circle is pie x d,
    but if the area be declared,
    the formula is pie x r squared!

    Learn this and then use it. Obviously, d is diameter and r is radius!

    Enjoy!
    • 0 followers
    Offline

    ReputationRep:
    pie r squared where r is half the diameter
    • 0 followers
    Offline

    ReputationRep:
    Sounds about right 2 me. Is this work 4 2morrow lol?:p:
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Louismoore16)
    right so just let me check ive done this question right and if i have im sorted
    the question was find the area of a circle by using diameter=14.8cm
    so i do 14.8 divided by 2=7.4 pie time 7.4 squared=172.3

    is this correct?
    You've changed the question slightly. In your first post, you said the diameter = 12.3

    But anyway, if the diameter is 14.8cm, then the area is 172.0336... (not 172.3), but you'd probably want to round that down to 172cm squared.
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    ok thanks for all you help
    L-C-17: this is for my maths homework lol
    Tomthecool: i changed the question half way throught to 14.8 so i could check if i go it right
    and IChem: yes i ment to put 172.03 but my key is abit sticky lol
    and sorry about posting so much of the same thing, my page kept refreshing and sending.

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: September 23, 2008
New on TSR

Join the Welcome Squad

Become a part of the TSR team!

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.