Annulus

The radius of the larger circle is 8cm, the radius of smaller is 5cm. Calculate the contents of the annulus.

Correct answer:

S =  122.5221 cm²

Step-by-step explanation:

$$\begin{gathered} r_1=8\text{ cm } \\ {r}_2=5\text{ cm } \\ {S}_1=\pi \cdot r_1^2=3.1416\cdot 8^2\doteq 201.0619 \\ {S}_2=\pi \cdot r_2^2=3.1416\cdot 5^2\doteq 78.5398 \\ S=S_1-S_2=201.0619-78.5398=122.5221{\text{cm}}^2 \end{gathered}$$

Try another example

Related math problems and questions:

• Annulus
  Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the content area of the annulus.
• Annulus
  Calculate the area of two circles annulus k₁ (S, 3 cm) and k₂ (S, 5 cm).
• 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.
• 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?
• 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?
• Circle - easy 2
  The circle has a radius 6 cm. Calculate:
• 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?
• Radius of the circle
  Calculate the radius of the circle whose length is 107 cm larger than its diameter
• Quadrant II
  Calculate the radius of the quadrant, which area is equal to area of circle with radius r = 15 cm.
• 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.
• 22/7 circle
  Calculate approximately the area of a circle with radius 20 cm. When calculating π, use 22/7.
• Radius
  Find the radius of the circle with area S = 200 cm².
• Circle area
  Calculate the circle area with a radius of 1.2 m.
• Calculate
  Calculate the area of a circle whose radius is 5 dm.
• Four circles
  1) Calculate the circle radius if its area is 400 cm square 2) Calculate the radius of the circle whose circumference is 400 cm. 3) Calculate circle circumference if its area is 400 cm square 4) Calculate the circle's area if perimeter 400 cm.
• 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?
• Diameters of circles
  How many percent of the area of a larger circle is a smaller circle if the smaller circle has a diameter 120 mm and a larger one has a diameter 300 mm?