Question

The circle-shaped part of the necklace above has a diameter of 4 mm. The circumference of the circle-shaped part of each of the earrings is one-half the circumference of the necklace. What is the circumference of the circle-shaped part of one of the earrings? (Use 3.14 for .)

Answer 1

6.28 mm

Explanation:

We have been given the diameter of circle shape necklace

`Radius=(diameter)/(2)`

`Radius=(4)/(2)=2`

So, the radius of circle shape necklace is 2mm

Using the formula for circumference which is:
`2\pi\cdot r`

Circumference of necklace of circle shaped is:

`2\cdot3.14\cdot2`

`\Rightarrow 12.56mm`

And as we are given that the circumference of of the earrings is one-half the circumference of the necklace.

Hence, the the circumference of the circle-shaped part of one of the earrings:

`(1)/(2)\cdot 12.56`

`\Rightarrow 6.28`