Answer:
7a) The diameter is 10 feet
7b) The area is 78.5 feet²
Explanation:
The circumference of the rug is 31.4 feet as stated in the question. (the ribbon tied around the circumference is 31.4 ft)
The formula for the circumference of a circle is 2πr
In this case 2πr=31.4
2πr=31.4
Divide both sides by π(3.14)
2r=10
You don't need to find r for the first question because 2r is the diameter. But r is 5 anyway.
For 7b), the formula for the area of a circle is πr². Using our radius we found out earlier, we have π*5² or 25π which, using 3.14 as π, is 78.5 square feet