Question

If the circumference of a circle with diameter 1 unit is about 3.14 units,

Then calculate the approximate length of the circumference of a circle that has:

a. 1.5 cm diameter b). 3.5 cm diameter c). radius is 1.62 cm

Answer 1

Answer :

Given : circumference of a circle with diameter 1 unit is about 3.14 units .
We know
Circumference = $\mathrm{\pi }$$\times$ d
Where
d = diameter
So according to question we get

3.14 = $\mathrm{\pi }$$\times$ 1

$\mathrm{\pi }$ = 3.14
So,
Circumference when
a ) diameter = 1.5 cm and $\mathrm{\pi }$ = 3.14
So,
circumference = 1.5 $\times$ 3.14 = 4.71 cm ( Ans )

b ) Diameter = 3.5 cm and $\mathrm{\pi }$ = 3.14
So,
Circumference = 3.5 $\times$ 3.14 = 10.99 ( Ans )

c ) Radius = 1.62 cm and $\mathrm{\pi }$ = 3.14
We know diameter = 2 $\times$ radius
So
Diameter = 2 $\times$ 1.62 = 3.24 cm
Then
Circumference = 3.24 $\times$ 3.14 = 10.1736 cm ( Ans )