← Back to the activity

Year 7 Maths — Circles: centre, radius and diameter

Name the centre, radius and diameter of a circle, and use the fact that the diameter is twice the radius.

Name: ________________________

  1. 1.A circle has a radius of 6 cm. What is its diameter, in centimetres?

    • a) 36
    • b) 3
    • c) 12
    • d) 6

  2. 2.A circle has a diameter of 20 cm. What is its radius, in centimetres?

    • a) 20
    • b) 40
    • c) 10
    • d) 5

  3. 3.The diameter of a circle is always...

    • a) three times the radius
    • b) half the radius
    • c) twice the radius
    • d) the same as the radius

  4. 4.Every measurement here is in centimetres. Sort each circle by whether its diameter is below 20 or above 20.

    Groups: Diameter below 20 · Diameter above 20

    • radius 8
    • radius 15
    • radius 6
    • radius 12
    • diameter 26
    • diameter 15

  5. 5.Match each circle's radius to the diameter of the same circle.

    • radius 3
    • radius 5
    • radius 8
    • radius 11
    • 10
    • 22
    • 16
    • 6

  6. 6.Tap the radius.

    Write the number of the part.

    123

  7. 7.What is the name for the point exactly in the middle of a circle?

  8. 8.A round table top has a diameter of 90 cm. How far is it from the middle of the table to its edge, in centimetres?

    • a) 90
    • b) 180
    • c) 45
    • d) 30

Answer key — Year 7 Maths — Circles: centre, radius and diameter

  1. 1. c) 12
  2. 2. c) 10
  3. 3. c) twice the radius
  4. 4. radius 6 → Diameter below 20; radius 12 → Diameter above 20; diameter 15 → Diameter below 20; diameter 26 → Diameter above 20; radius 8 → Diameter below 20; radius 15 → Diameter above 20
  5. 5. radius 3 → 6; radius 5 → 10; radius 8 → 16; radius 11 → 22
  6. 6. 1 — The radius
  7. 7. centre
  8. 8. c) 45