Midpoints of any quadrilateral form a parallelogram

Midpoints of any quadrilateral form a parallelogram

IP 4
8 marks
  1. In triangle \(OAB\), \(M\) and \(N\) are the midpoints of \(OA\) and \(OB\). Using vectors, show that \(MN\) is parallel to \(AB\) and half its length.[3]
  2. \(ABCD\) is any quadrilateral, and \(P\), \(Q\), \(R\), \(S\) are the midpoints of \(AB\), \(BC\), \(CD\), \(DA\). Using position vectors \(\mathbf a\), \(\mathbf b\), \(\mathbf c\), \(\mathbf d\), prove that \(PQRS\) is a parallelogram.[4]
  3. State the condition on the diagonals of \(ABCD\) for \(PQRS\) to be a rhombus.[1]

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:(a) \(\overrightarrow{MN}=\dfrac12\overrightarrow{AB}\) (b) \(\overrightarrow{PQ}=\overrightarrow{SR}=\dfrac12\overrightarrow{AC}\) (c) \(AC=BD\)

Need help? Join our IP Math tuition programme.

Learn more