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What is the circumference of a circle with radius of 21 cm?
Well, darling, the circumference of a circle is calculated using the formula C = 2πr. So, with a radius of 21 cm, you just plug that bad boy in and get C = 2 x π x 21 = 132 cm. Voilà, there you have it!
What is the diameter of a circle with a radius of 21 ft?
If radius=21 ft, then diameter = 2*radius = 42 ft
Diameter of 66 inch circumference?
To find the diameter of a circle with a circumference of 66 inches, you can use the formula C = πd, where C is the circumference and d is the diameter. Rearranging the formula to solve for d, you get d = C / π. Plugging in the circumference of 66 inches, the diameter would be 66 / π ≈ 21 inches.
How many square feet in a 42 inch diameter circle?
Well, let's imagine that circle as a happy little friend on our canvas. To find the square footage, we first need to find the radius by dividing the diameter by 2. So, with a 42-inch diameter, the radius would be 21 inches. Then we can use the formula for the area of a circle, which is π times the radius squared. Just remember, there are about 0.00595 square feet in one square inch, so you can use that to convert your final answer.
How far does the tip of the minute hand of a clock move in 35 minutes if the hand is 9 inches long?
Assuming the 9 inches is from the pivot point to the tip of the minute hand: In 1 hour = 60 minutes the tip of the minute hand sweeps out the circumference of a circle with radius 9 inches. In 35 minutes, it sweeps out a fraction on 35 minutes/1 hour of this. The circumference of a circle is given by circumference = 2 × π × radius Therefore the tip of the minute hand moves: length = 35/60 × 2 × π × 9 in → length = 21/2 π in = 10½ π in ≈ 33.0 in
