Question

A circle has a diameter of 121 inches.

Which equation can be used to find the radius of this circle?

r=121/2π

r=1/2(121)

r=121π

r=2(121)

Answer 1

You would use the equation -r=1/2(121) to find the radius of that circle as the radius is half the diameter 

Answer 2

option 2nd is correct

`r= (1)/(2) (121)` inches

Explanation:

Diameter of a circle is given by:

d = 2r

where,

d is the diameter

r is the radius of the circle.

As per the statement:

A circle has a diameter of 121 inches.

⇒
`d = 121` inches

Using formula:

`d = 2r`

then;

`121 = 2r`

or

2r = 121

Divide both sides by 2 we have;

`r= (1)/(2) (121)` inches

therefore, an equation can be used to find the radius of this circle is,
`r= (1)/(2) (121)` inches