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6 votes
6 votes
8. For circle A, the circumference is 31.4 ft. What is the area? Use 3.14 for pi

314 ft²

15.7ft²

78.5 ft²

9.9 ft²

User Neph
by
2.4k points

2 Answers

13 votes
13 votes
To solve this problem, you need to find a radius... Circumference=2(3.14)(r)

2(3.14)=6.28

31.4/6.28=5=radius

A=(3.14)(r^2)

A=(3.14)(5^2)=78.5

Area= 78.5 ft^2
User Youssef Boudaya
by
2.9k points
16 votes
16 votes

Answer:


\huge\boxed{\sf A = 78.5\ ft\²}

Explanation:

Circumference = C = 31.4 ft

We know that,

C = 2πr

Where, r is the radius

31.4 = 2(3.14)r

31.4 = 6.28(r)

Divide 6.28 to both sides

31.4/6.28 = r

5 ft. = r

r = 5 ft.

Now,

Finding area:

A = πr²

A = (3.14)(5)²

A = (3.14)(25)

A = 78.5 ft²


\rule[225]{225}{2}

User Wouter B
by
3.0k points