Child's Homework Problem

imhotep

Well-known member
  • Mar 29, 2017
    14,823
    8
    35,324
    113
    Below is a daughter's homework problem posted by her father Sir Timothy Gowers. He's a Fields Medal winner (like the Nobel Prize for Mathematicians) and currently Professeur titulaire de la chaire Combinatoire, which translates as the holder of the Combinatorics chair at at the Collège de France, formerly the Prof of Maths at Cambridge.

    BTW his daughter scored 39/40 with this marked as wrong as she gave the answer as "infinity"

    What do you think the answer is? :unsure:

     

    tharakaf

    Well-known member
  • Oct 19, 2020
    34,903
    71,079
    113
    Below is a daughter's homework problem posted by her father Sir Timothy Gowers. He's a Fields Medal winner (like the Nobel Prize for Mathematicians) and currently Professeur titulaire de la chaire Combinatoire, which translates as the holder of the Combinatorics chair at at the Collège de France, formerly the Prof of Maths at Cambridge.

    BTW his daughter scored 39/40 with this marked as wrong as she gave the answer as "infinity"

    What do you think the answer is? :unsure:


    Not sure about the circle, but for the rest it should be (number of sides - 2) x 180

    based on that infinity should be the correct answer for the circle since circle is technically an infinite number of sides coming together :unsure: :unsure:
     
    • Like
    Reactions: imhotep

    imhotep

    Well-known member
  • Mar 29, 2017
    14,823
    8
    35,324
    113
    360 degrees ? :rolleyes:-circle
    This question is a bit ambiguous. If you go by the n sided polygon formula you would think the answer is "infinity" but it's not the right answer.
    The problem is the interpretation of the word "Inside".
    With a polygon inside refers to the sum of the interior angles, which is of course as many correctly said here (n-2)*180 degrees.

    However, with a circle it refers to the measure of the Central Angle. With a circle it is 360 degrees which is a fundamental property of circles in geometry.
     
    • Love
    Reactions: jamiezue

    MrFrog

    Well-known member
  • Jun 25, 2018
    2,339
    2,908
    113
    මාතර
    This question is a trap :lol: . If it was asked in a separate question, the student could have got it right.
    Btw, we sometimes think a circle as a polygon with infinite sides and vertices. But can we really use that as a fact in mathematics?
     

    imhotep

    Well-known member
  • Mar 29, 2017
    14,823
    8
    35,324
    113
    This question is a trap :lol: . If it was asked in a separate question, the student could have got it right.
    Btw, we sometimes think a circle as a polygon with infinite sides and vertices. But can we really use that as a fact in mathematics?
    It should not have been asked as it's not very clear to a student. BTW a circle doesn't have infinite sides either.

    The apeirogon is an extension of the definition of regular polygon to a figure with an infinite number of sides. It's derived from the Greek word Aperios ἄπειρος” which means infinite or boundless. Apeirogons are the two-dimensional case of infinite polytopes.

    A circle has 0 sides. Check the definition of a side/edge.

    PS: You can still consider to think a circle as an extension of a polygon with infinite sides and arrive at useful results. This is exactly the approach that Archimedes, Liu Hui, and many others have used down the centuries to study circular geometry, including coming up with approximations for π and the area of the circle πr^2.
     
    • Love
    Reactions: MrFrog