Results 1 to 6 of 6

Math Help - Radian measure & its application

  1. #1
    Member
    Joined
    Sep 2007
    Posts
    198

    Radian measure & its application

    Please help me to solve the following problem.

    A sector of a circle of radius r cm contains an angle of 1.2 radians. Given that the sector has the same perimeter as a square of area 36 cm^2, find the value of r.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by geton View Post
    Please help me to solve the following problem.

    A sector of a circle of radius r cm contains an angle of 1.2 radians. Given that the sector has the same perimeter as a square of area 36 cm^2, find the value of r.
    You're kidding, right? Urgent homework on Christmas day. What is it - a last minute present for someone?

    You should get that the perimeter of the square is 24 cm.
    You should have a formula for arclength. Use it. The perimeter of the sector will be arclength + 2r = (.....) r.

    Then 24 = (.....) r => r = ........
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Sep 2007
    Posts
    198
    Quote Originally Posted by mr fantastic View Post
    You're kidding, right? Urgent homework on Christmas day. What is it - a last minute present for someone?

    You should get that the perimeter of the square is 24 cm.
    You should have a formula for arclength. Use it. The perimeter of the sector will be arclength + 2r = (.....) r.

    Then 24 = (.....) r => r = ........
    Oh.. Iíve full respect about the Christmas day, but Iím from different country & religion.
    Happy Christmas to all of you. And thank you to help me even in this holyday.

    But Iíve to understand how you got perimeter of the square is 24 cm? Please tell me.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by geton View Post
    Oh.. Iíve full respect about the Christmas day, but Iím from different country & religion.
    Happy Christmas to all of you. And thank you to help me even in this holyday.

    But Iíve to understand how you got perimeter of the square is 24 cm? Please tell me.
    the area of a rectangle is length times width. so the area of a square is the length of a side squared (since the length and width are equal). thus, the side length of the of a square with area 36 cm^2 is \sqrt{36} = 6. so the perimeter is 4 times this length, since the perimeter is the sum of the length of all the sides. thus we get 24
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Sep 2007
    Posts
    198
    Thank you so much.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Lord of certain Rings
    Isomorphism's Avatar
    Joined
    Dec 2007
    From
    IISc, Bangalore
    Posts
    1,465
    Thanks
    6
    Quote Originally Posted by geton View Post
    And thank you to help me even in this holyday.
    holyday! Isn't that a good candidate for a cryptic crossword clue?
    Thanks geton
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Radian Measure
    Posted in the Trigonometry Forum
    Replies: 7
    Last Post: July 17th 2011, 05:30 PM
  2. Radian measure
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: November 24th 2009, 03:59 PM
  3. Radian Measure
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: November 24th 2009, 03:10 AM
  4. Radian Measure?
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: March 14th 2009, 06:49 PM
  5. Radian measure
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: November 23rd 2008, 03:19 PM

Search Tags


/mathhelpforum @mathhelpforum