The radius of the big circle is twice that of the small circle. The area of the big circle is 12 square decimeters larger than that of the small circle. What is the area of the big circle?

The radius of the big circle is twice that of the small circle. The area of the big circle is 12 square decimeters larger than that of the small circle. What is the area of the big circle?

The great circle covers an area of 16 square decimeters
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If the radius of the big circle is twice that of the small circle, then the area of the big circle is four times that of the small circle, because the area formula is π R & # 178
The area of the big circle is 12 square decimeters larger than that of the small circle, that is to say, three times the area of the small circle is 12, then the area of the small circle is 4, so the area of the big circle is 16

There are big circle, small circle and small circle. Their area difference is 62.8 square decimeters, and the radius of the big circle is 1.5 times that of the small circle. What are the areas of the two circles

Because the radius of the big circle is 1.5 times that of the small circle, the area of the big circle is 2.25 times that of the small circle,
Small circle area = 62.8 / (2.25-1) = 50.24 square decimeters
Large circle area = 50.24 * 2.25 = 113.04 square decimeters

There are two circles, big and small. The area difference between them is 62.8 square decimeters, and the radius of the big circle is 1.5 times that of the small circle. What are the areas of the two circles?

Let the radius of small circle be r, then the radius of large circle is 1.5R = 3R / 2
S big circle = π * (3R / 2) ^ 2 = 9 π * R ^ 2 / 4
S small circle = π * R ^ 2
S big circle - s small circle = 5 π * R ^ 2 / 4 = 62.8
That is, R ^ 2 = 16
So s small circle = 16 π = 50.24
S big circle = 36 π = 113.04

There are two circles, big and small. The area difference between them is 62.8 square decimeters, and the radius of the big circle is 1.5 times that of the small circle. What are the areas of the two circles