Paper 2 · Co-ordinate Geometry of the Line ⏱ Tested in 2 exam questions since 2017 Lesson 8 of 9

The Line 8 – Construction 21 – Centroid

This tutorial is for members

Read the lesson notes free below — subscribe to watch the full worked video and download the PDF.

Subscribe for full access · €199/yr

You’ll learn

  • Construct the centroid with ruler and compass by drawing two medians
  • Use the 2:1 ratio — the centroid sits two-thirds along each median from the vertex
  • Compute the centroid with the section formula (2:1) from a vertex to the opposite midpoint
  • Check silently with ((x₁+x₂+x₃)/3, (y₁+y₂+y₃)/3) — not as written exam working

Most recent exam questions

  • 2024 P2 Q4(a)
  • 2017 P2 Q3(a)
  • 2017 P2 Q3(b)

💬 Stuck on something in this lesson?

Send your question with this lesson’s name attached — you’ll get a reply by email.