Annulus Problems

Annulus is a ring-shaped object, a region bounded by two concentric circles.

Number of problems found: 29

The collar
The collar on the dress has the shape of an annulus 6 cm wide. The circumference of the inner circle is 31.4 cm. How much cm² of fabric is needed to make one collar?
Round skirt
The cut on the round skirt has the shape of an annulus. Determine how much m² of fabric will be consumed on an 80 cm long skirt. The circumference of the waist is a circle with a smaller radius and is 69 cm.
Brass sphere
Find the weight of a brass ball with an outer radius of 12 cm, a wall thickness of 20 mm if the brass's density is 8.5 g/cm³.
The hollow cylinder
The hollow cylinder has a height of 70 cm, an outer diameter of 180 cm, and an inner diameter of 120 cm. What is the surface of the body, including the area inside the cavity?
Annulus from triangle
Calculate the content of the area bounded by a circle circumscribed and a circle inscribed by a triangle with sides a = 25mm, b = 29mm, c = 36mm
Round flowerbed
Around a round flowerbed with a diameter of 6 meters and I will make a sidewalk up to 0.5 meters wide. How much gravel is needed if the layer is to be 5 cm high?
Annulus
Two concentric circles with radii 1 and 9 surround the annular circle. This ring is inscribed with n circles that do not overlap. Determine the highest possible value of n.
Steel tube
The steel tube has an inner diameter of 4 cm and an outer diameter of 4.8 cm. The density of the steel is 7800 kg/m³. Calculate its length if it weighs 15 kg.
Annular area
The square with side a = 1 is inscribed and circumscribed by circles. Find the annular area.
Mice
Mice consumed a circular hole in a slice of cheese. The cheese has the shape of a circular cut with a radius of 20 cm and an angle of 90 degrees. What percentage of the cheese ate mice if they made 20 holes with a diameter of 2 cm?
Metal tube
Calculate the metal tube mass 8dm long with the outer radius 5cm and the inner radius 4.5cm and 1cm³ of this metal is 9.5g.
Concentric circles
There is given a Circle K with a radius r = 8 cm. How large must a radius have a smaller concentric circle that divides the circle K into two parts with the same area?
Masquerade ball
Marie wants to make a cone-shaped witch's hat for a masquerade ball. How much material will it need if it counts on an annular rim with diameters of 28cm and 44cm? Hat side length is 30cm. Add 5% of the material to the bust. Round to cm².
Circle annulus
There are 2 concentric circles in the figure. Chord of larger circle 10 cm long is tangent to the smaller circle. What are does annulus have?
Around
Around the circular flowerbed with a radius of 2 m is a sidewalk 80 cm wide. How many square meters does the sidewalk have?
The coil
How many ropes (the diameter 8 mm) fit on the coil (threads are wrapped close together) The coil has dimension: the inner diameter 400mm, the outside diameter 800mm and the length of the coil is 470mm
Two annuluses
The area of the annular circle formed by two circles with a common center is 100 cm². The radius of the outer circle is equal to twice the radius of the inner circle. Determine the outside circle radius in centimeters.
Pipe cross section
The pipe has an outside diameter 1100 mm and the pipe wall is 100 mm thick. Calculate the cross section of this pipe.
Annulus
The radius of the larger circle is 8cm, the radius of smaller is 5cm. Calculate the contents of the annulus.
The pipe
The pipe is 1.5 m long. Its outer diameter is 60 cm, inner diameter is 52 cm. Calculate the pipe's weight if the material's density from which it is made is 2 g/cm³. Round the results to whole kilograms.

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