Circumference and Area of Circles

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can someone help me with these:Find the radius, diameter and circumference of a circle with an area of 64 cm2. Write your answers as decimals rounded to the nearest hundredth.

Find the circumference and area of a circle that has a rectangle inscribed inside it with sides that are 9 by 12 centimeters. Write your answer as decimals rounded to the nearest hundredth. (hint: Draw this circle on your paper and find the length of the diagonal of the rectangle.)

you should know that Area = πr^2
and circumference is 2πr
and clearly the diameter is 2r

ao πr2=64
r = 8/√π

evaluate using your calculator and substitute in the above expressions.
Round off AFTER you have substituted,not before.

For your second question they have given you an excellent hint.
I will give you one more...
the radius of the circle is half the length of the diagonal of the rectangle.

• Circumference and Area of Circles -

a 9x12 rectangle has diagonals of
d = ã(9^2 + 12^2) = ã225 = 15

since these diagonals are also the diameter off the circle

A = ƒÎ (d/2)^2 = ƒÎ (15/2)^2 = 176.7

C = ƒÎd = ƒÎ(15) = 47.123

• Circumference and Area of Circles -

a 9x12 rectangle has diagonals of
d = square root of(9^2 + 12^2) = square root of 225 = 15

since these diagonals are also the diameter off the circle

A = pi (d/2)^2 = pi (15/2)^2 = 176.7

C = pi times d = pi(15) = 47.123

• Circumference and Area of Circles -

This question Find the circumference and area of a circle that has a rectangle inscribed inside it with sides that are 9 by 12 centimeters. Write your answer as decimals rounded to the nearest hundredth. (hint: Draw this circle on your paper and find the length of the diagonal of the rectangle.) is copyrighted material of Florida Virtual School. Please remove it and any solutions.

• Circumference and Area of Circles -

None of these are correct! Try doing your own work instead of copying off of stupid people that don't understand math!!!

• Circumference and Area of Circles -

waht do we do on circumfrence?

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