jˈuːzɪŋ ɐ fjˈuː stɹˈeɪt lˈaɪnz tʊ ɐpɹˈɑːksɪmˌeɪt ðə lˈɛŋθ əvə kˈɜːv wɪl pɹədˈuːs ɐn ˈɛstᵻmət lˈoʊɚ ðɐn ðə tɹˈuː lˈɛŋθ; wˌɛn ɪŋkɹˈiːsɪŋli ʃˈɔːɹt ænd ðˈʌs mˈoːɹ nˈuːmɚɹəs lˈaɪnz ɑːɹ jˈuːzd, ðə sˈʌm ɐpɹˈoʊtʃᵻz ðə kˈɜːvz tɹˈuː lˈɛŋθ.
Using a few straight lines to approximate the length of a curve will produce an estimate lower than the true length; when increasingly short (and thus more numerous) lines are used, the sum approaches the curve's true length.