Question

A circle has a radius of 5 units, 3 students tried to calculate the circumference of the circle, put their answers in order from most accurate to least accurate31.4π units 10π units 31.4 units

Answer 1

A circle has a radius of 5 units, 3 students tried to calculate the circumference of the circle, put their answers in order from most accurate to least accurate

31.4π units

10π units

31.4 units ​

we know that

the circumference of a circle is equal to

`C=2\pi r`

we have

pi=3.14

r=5 units

substitute

`\begin{gathered} C=2\pi(5) \\ C=10\pi\text{ units} \end{gathered}`

the exact value is 10pi units

the approximate value (assume pi=3.14)

C=31.4 units

so

order from most accurate to least accurate is

10π units

31.4 units

31.4π units

order from least accurate to most accurate is

31.4π units

31.4 units

10π units