Question

The circumference of a circle is 10.4mm.

Find the length of the diameter.
Give your answer rounded to 3 SF.

Answer 1

diameter = 3.31 mm (3 sf)

Step-by-step explanation:

• Diameter of a circle (d) = 2r (where r is the radius)
• Circumference of a circle = 2
  `\pi`r (where r is the radius)
  ⇒ circumference =
  `\pi`d

Given:

• circumference = 10.4 mm

⇒
`\pi`d = 10.4

⇒ d = 10.4 ÷
`\pi` = 3.31 mm (3 sf)

Answer 2

diameter: 3.31 mm

Step-by-step explanation:

circumference of circle → πd

using the formula:

10.4 = πd

d = 10.4/π

d = 3.31 mm