Answer:
[tex]\boxed {\boxed {\sf C. \ 4 \ inches}}[/tex]
Step-by-step explanation:
Circumference is the perimeter of a circle. It can be found using the formula:
[tex]c= \pi d[/tex]
However, we are given the radius.
- The radius measures from the center to the edge of the circle.
- The diameter measures from edge to edge through the center.
- So, the diameter is twice the radius, or d=2r
The formula can be rewritten as:
[tex]c= \pi 2 r[/tex]
We know the circumference is 25.12 inches.
[tex]25.12 \ in = \pi 2r[/tex]
Let's round pi to 3.14
[tex]25.12 \ in = (3.14) 2r[/tex]
We want to solve for the radius, so we must isolate it.
Divide both sides by 3.14 because the inverse of multiplication is division.
[tex]25.12 \ in / 3.14= (3.14 ) 2r / 3.14[/tex]
[tex]8 \ in = 2r[/tex]
Divide both sides by 2.
[tex]8 \ in / 2 = 2r/2[/tex]
[tex]4 \ in = r[/tex]
The radius of the disc is 4 inches.
