GCSE · Constructions & loci

Ruler-and-compass constructionsExam-style questions

The four standard constructions — perpendicular bisector, angle bisector, perpendicular from/at a point, and 60° — why each one works, and why the construction arcs must be left on the page.

10 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    (a) Using ruler and compasses, construct triangle ABCABC with AB=7AB = 7 cm, BC=6BC = 6 cm and AC=5AC = 5 cm.

    (b) Construct the perpendicular bisector of BCBC and the bisector of angle BACBAC. Extend both constructed lines far enough for them to cross, and mark the crossing point XX. (You may find that XX lies outside the triangle.)

    (c) Ravi says "XX is the same distance from BB as from CC, and it is also the same distance from ABAB as from ACAC." Explain why Ravi is right.
    Level 5 · 6 marksTry it
  2. 2
    Using ruler and compasses only, construct an angle of 75°75°. You must show all your construction arcs.

    Hint: 75=60+1575 = 60 + 15.
    Level 5 · 4 marksTry it