Circles
The areas of the two circles are in the ratio 2:20. The larger circle has a diameter 20. Calculate the radius of the smaller circle.
Correct answer:

Tips for related online calculators
Check out our ratio calculator.
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
You need to know the following knowledge to solve this word math problem:
Units of physical quantities:
Grade of the word problem:
We encourage you to watch this tutorial video on this math problem: video1
Related math problems and questions:
- Calculate 3167
The area of the two circles is in a 4: 9 ratio. The larger circle has a diameter of 12 cm. Calculate the radius of the smaller circle.
- Calculate 12061
The area of the two circles is in a 4: 9 ratio. The larger circle has a diameter of 18 cm. Calculate the radius of the smaller circle.
- Diameters of circles
How many percent of the area of a larger circle is a smaller circle if the smaller circle has a diameter of 120 mm and a larger one has a diameter of 300 mm?
- Annulus
Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the area of the annulus.
- Circumference 3589
Calculate the circle's radius if the circumference and area are in a 2: 5 ratio.
- Circle annulus
There are two concentric circles in the figure. The chord of the larger circle, 10 cm long, is tangent to the smaller circle. What does annulus have?
- Annulus
The radius of the larger circle is 8cm, the radius of smaller is 5cm. Calculate the area of the annulus.
- Circumference 8395
The circle's circumference is 321dm larger than the diameter of the circle. What is the average?
- The ratio
The ratio of the lengths of the two circles is 5: 2. Find the ratio of a a) the radii of these circles b) the areas for these circles
- Square and circles
The square in the picture has a side length of a = 20 cm. Circular arcs have centers at the vertices of the square. Calculate the areas of the colored unit. Express area using side a.
- Concentric circles
In the circle with diameter, 13 cm is constructed chord 1 cm long. Calculate the radius of a concentric circle that touches this chord.
- Rectangular triangles
The lengths of corresponding sides of two rectangular triangles are in the ratio 2:5. At what ratio are medians relevant to hypotenuse these right triangles? At what ratio are the areas of these triangles? A smaller rectangular triangle has legs 6 and 8 c
- Smaller 17093
There are two gears in the wall clock. The larger wheel has 54 teeth, and the smaller 24 teeth. How many times does the small wheel turn if the big one turns four times?
- Snowman 2
On the medal, which has the shape of a circle with a diameter $D cm is sketched snowman so that the following requirements are met: 1. snowman is composed of three circles, 2. space over snowman is the same as under it, 3. diameters of all circles express
- Snowman
In a circle with a diameter 50 cm are drawn 3 circles /as a snowman/ where: its diameters are integers, each larger circle diameter is 3 cm larger than the diameter of the previous circle. Determine snowman height if we wish the highest snowman.
- Smaller 4835
There are two gears in the wall clock. The larger wheel has 54 teeth, and the smaller 24 teeth. How many times does the small wheel turn if the big one turns four times?
- Radius of the circle
Calculate the radius of the circle whose length is 107 cm larger than its diameter