Results are out! Find what you need...fast. Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post

Geometry - finding radius of 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:
    A circle is circumscribed about an isosclese triangle whose sides have lengths 13, 13, and 24cm

    Find the radius of the circle

    a diagram wasnt given but its basically a triangle with a circle around it

    I started of by finding the height of the triangle which is 5cm but i duno what to do next..

    any help?

    Thanks in advance
    • 4 followers
    Offline

    ReputationRep:
    You are more likely to get a response here.

    Anyyhow, have you heard of the extended sine rule?

    Spoiler:
    Show
    the diameter of the circumcirlce is equal to the ratio of a side to the sine of an opposite angle. Combine this with the cosine rule
    • 5 followers
    Offline

    ReputationRep:
    (Original post by helpmee1234567890)
    A circle is circumscribed about an isosclese triangle whose sides have lengths 13, 13, and 24cm

    Find the radius of the circle

    a diagram wasnt given but its basically a triangle with a circle around it

    I started of by finding the height of the triangle which is 5cm but i duno what to do next..

    any help?

    Thanks in advance
    I have worked out the answer to be 16.9

    If that agrees with the answer in your book, let me know and I'll send you the solution (hard to explain without showing you a drawing) but essentially it uses the fact that there's a right angled triangle in a semi-circle and pythagoras with simultaneous equations.
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    (Original post by dugdugdug)
    I have worked out the answer to be 16.9

    If that agrees with the answer in your book, let me know and I'll send you the solution (hard to explain without showing you a drawing) but essentially it uses the fact that there's a right angled triangle in a semi-circle and pythagoras with simultaneous equations.
    Hey
    yeh thats the answer I found it in the end but thanks

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: April 1, 2012
New on TSR

Personal statement help

Use our clever tool to create a PS you're proud of.

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