GCSE · Angles & polygons

Angle rules & giving reasonsExam-style questions

Why angles at a point make 360°, angles on a straight line make 180°, and vertically opposite angles are equal; the triangle and quadrilateral angle sums; isosceles triangles; and how to write the reasons examiners insist on.

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

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    ABCABC is a triangle with AB=ACAB = AC. BCDBCD is a straight line.

    Angle BAC=44°BAC = 44°.44°xABCDDiagram NOT accurately drawn

    Work out the size of the angle marked xx. You must give reasons for each stage of your working.
    Level 3 · 5 marksTry it
  2. 2
    The diagram shows a triangle.(2x + 10)°(3x − 20)°(x + 40)°Diagram NOT accurately drawn

    Work out the size of the largest angle of the triangle.
    Level 3 · 3 marksTry it
  3. 3
    The diagram shows four angles meeting at a point.114°2x°x°Diagram NOT accurately drawn

    Work out the size of the angle marked 2x°2x°.
    Level 3 · 3 marksTry it
  4. 4
    Triangle PQRPQR has PQ=PRPQ = PR.

    Angle PQR=65°PQR = 65°.65°PQRDiagram NOT accurately drawn

    Work out the size of angle QPRQPR. Give a reason for each stage of your working.
    Level 3 · 3 marksTry it
  5. 5
    The diagram shows two straight lines crossing at a point.(3x + 10)°76°Diagram NOT accurately drawn

    Work out the value of xx. Give a reason for your answer.
    Level 3 · 3 marksTry it