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Class 6 Maths — Basic geometrical ideas

Tell points, lines, rays and line segments apart, name the parts of an angle and a circle, and count the sides and diagonals of a polygon.

Name: ________________________

Before you start

Three lines are drawn on this circle. Take them in turn and find out what each one is called, looking at where each one starts and where it ends.

123
  1. 1. Radius — centre to edge
  2. 2. Diameter — right across, through the centre
  3. 3. Chord — edge to edge, missing the centre

Every diameter is also a chord — it is simply the longest one, and the only kind that passes through the centre.

  1. 1.An angle is made where two rays meet at a point. How many arms does one angle have?

  2. 2.Sort each name by whether it describes a part of a circle or a part of an angle.

    Groups: Part of a circle · Part of an angle

    • Diameter
    • Chord
    • Centre
    • Radius
    • Arm
    • Vertex

  3. 3.Three straight lines have been drawn on this circle. Tap the diameter.

    Write the number of the part.

    123

  4. 4.How many line segments make up the sides of a hexagon?

  5. 5.Three straight lines have been drawn on this circle. Tap the chord that is not a diameter.

    Write the number of the part.

    123

  6. 6.A line has no ends, a ray has one end, and a line segment has two. Which of the three has a length you could measure with a ruler?

    • a) A ray
    • b) All three of them
    • c) A line
    • d) A line segment

  7. 7.How many diagonals can be drawn inside a quadrilateral?

  8. 8.Match each shape to the number of sides it has.

    • Triangle
    • Quadrilateral
    • Pentagon
    • Hexagon
    • Octagon
    • 5
    • 8
    • 6
    • 4
    • 3

Answer key — Class 6 Maths — Basic geometrical ideas

  1. 1. 2
  2. 2. Radius → Part of a circle; Diameter → Part of a circle; Chord → Part of a circle; Centre → Part of a circle; Vertex → Part of an angle; Arm → Part of an angle
  3. 3. 2 — the line right across through the centre
  4. 4. 6
  5. 5. 3 — the line across the top
  6. 6. d) A line segment
  7. 7. 2
  8. 8. Triangle → 3; Quadrilateral → 4; Pentagon → 5; Hexagon → 6; Octagon → 8