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Help with the area and circumference of a circle

Help with the area and circumference of a circle-example-1

2 Answers

1 vote
Since we only know the diameter and the formulas use radius, we have to divide the diameter by two in both formulas. The trick is to remember the order of operations.

A= πr^2
A=(3.14)(5/2)^2
A=(3.14)(2.5)^2
A=(3.14)(6.25)
A=19.625 feet squared

Circumference=2πr
C=2(3.14)(5/2)
C=2(3.14)(2.5)
C=15.7 feet

Hope this helps! :)
User Spokey
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6.0k points
2 votes
Radius is 19.625
Divide 5 by 2 to get 2.5
Next multiply 2.5 by 2 to get 6.25
Then multiply 6.25 by 3.14 to get the answer

Circumference is 15.7
Multiply 3.14 by 5 to get the answer
User Amrabed
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6.1k points