Question

Given a circle with a circumference of 10cm, which equation shows how the relationship between a circumference and its diameter can be used to find π?

Question 1 options:

π=10d

π = 10d

π=d10

π=110d

Answer 1

The answer would be π=10d

Answer 2

`\pi =(C)/(2r)`

And replacing we got:

`\pi = (10 cm)/(2*r)`

Since we know that
`D = 2r` and
`r = (D)/(2)`

If we replace we got:

`\pi = (10 cm)/(2 *(D)/(2)) = (10)/(D)`

Explanation:

For this case we know the the circumference of the circle is 10 cm, and the formula for the circumference is given by:

`C= 2\pi r`

r = 10 cm

And if we solve for
`\pi` we can divide both sides by 2r we got:

`\pi =(C)/(2r)`

And replacing we got:

`\pi = (10 cm)/(2*r)`

Since we know that
`D = 2r` and
`r = (D)/(2)`

If we replace we got:

`\pi = (10 cm)/(2 *(D)/(2)) = (10)/(D)`