diff --git a/curriculum/challenges/english/18-project-euler/project-euler-problems-301-to-400/problem-311-biclinic-integral-quadrilaterals.md b/curriculum/challenges/english/18-project-euler/project-euler-problems-301-to-400/problem-311-biclinic-integral-quadrilaterals.md index 27ef30f5b3c..cd486bc5e73 100644 --- a/curriculum/challenges/english/18-project-euler/project-euler-problems-301-to-400/problem-311-biclinic-integral-quadrilaterals.md +++ b/curriculum/challenges/english/18-project-euler/project-euler-problems-301-to-400/problem-311-biclinic-integral-quadrilaterals.md @@ -16,7 +16,7 @@ We'll call $ABCD$ a biclinic integral quadrilateral if $AO = CO ≤ BO = DO$. For example, the following quadrilateral is a biclinic integral quadrilateral: $AB = 19$, $BC = 29$, $CD = 37$, $AD = 43$, $BD = 48$ and $AO = CO = 23$. -quadrilateral ABCD, with point O, an midpoint of BD +quadrilateral ABCD, with point O, a midpoint of BD Let $B(N)$ be the number of distinct biclinic integral quadrilaterals $ABCD$ that satisfy ${AB}^2 + {BC}^2 + {CD}^2 + {AD}^2 ≤ N$. We can verify that $B(10\\,000) = 49$ and $B(1\\,000\\,000) = 38239$.