Question

A circular mirror has a diameter of 30 inches and has a frame that is 3 inches thick. What is the circumference of the outer edge of the frame? Use 3.14 for π

π
. Round to the nearest inch.


19 inches
113 inches
104 inches
94 inches

Answer 1

By definition, the circumference of a circle is given by:

C=2πr

Where,

r: radius of the circle.

We have then, that the radius of the outer circle is given by:

r=15+3

r=18

Then, replacing values we have:

c=2(3.14)(18)

Answer:

The circumference of the outer edge of the frame is: 113 inches

option B

Answer 2

113 inches

Explanation:

Diameter of a circular mirror = 30 inches

The frame is 3 inches thick so the diameter of the circular mirror with the frame at each side will be 30 + 3 + 3 = 36 inches

Therefore, its radius will be 36/2 = 18 inches

We know the formula for the circumference of a circle:

Circumference =
`2\pi r`

So putting the value of the radius in this formula to get:

Circumference = 2 x 22/7 x 18 = 113 inches