Answer:
[tex]\boxed {\boxed {\sf About \ 5 \ centimeters }}[/tex]
Step-by-step explanation:
The area of a circle is found using this formula:
[tex]a= \pi r^2[/tex]
We know the area of the disc is 78.53 square centimeters and 3.14 is being used for pi.
[tex]78.53 \ cm^2 = (3.14) r^2[/tex]
We are solving for the radius, so we must isolate the variable r.
3.14 and r² are being multiplied. The inverse of multiplication is division, so divide both sides by 3.14
[tex]\frac{78.53 \ cm^2}{3.14} = \frac{(3.14) r^2}{3.14}[/tex]
[tex]\frac{78.53 \ cm^2}{3.14} =r^2[/tex]
[tex]25.0095541 \ cm^2 = r^2[/tex]
r is being squared, so we must take the square root of both sides.
[tex]\sqrt{25.0095541 \ cm^2} = \sqrt {r^2}[/tex]
[tex]\sqrt{25.0095541 \ cm^2} = r[/tex]
[tex]5.00095532 \ cm = r \\5 \ cm \approx r[/tex]
The radius of the disc is about 5 centimeters.
