There are three small circles in the diameter of the big circle. The diameter of the big circle is 5cm, and the diameter of the small circle is 2.5 cm, 1.5 cm and 1cm respectively. The sum of the circumference of the big circle and the three small circles is compared After comparison, which is longer? Which is shorter?

There are three small circles in the diameter of the big circle. The diameter of the big circle is 5cm, and the diameter of the small circle is 2.5 cm, 1.5 cm and 1cm respectively. The sum of the circumference of the big circle and the three small circles is compared After comparison, which is longer? Which is shorter?

The circumference of the great circle is 3.14 × 5 = 15.7 cm
The sum of the circumference of the small circle is 3.14 × 2.5 + 3.14 × 1.5 + 3.14 × 1 = 3.14 × (2.5 + 1.5 + 1) = 3.14 × 5 = 15.7cm
The circumference of the big circle is equal to the sum of the circumference of the small circle

The diameter of the small circle is 4cm, the radius of the big circle is 5cm, and the perimeter ratio of the big circle and the small circle is 5cm
If there are three natural numbers, the ratio of a to B is 3, the ratio of B to C is 4, and the sum of three numbers is 201, then a is a

2:5
Perimeter ratio = radius ratio = diameter ratio

If the radius of the small circle is 2cm long and the radius of the big circle is 5cm long, the perimeter of the small circle is a fraction of the perimeter of the big circle, and the area of the small circle is a fraction of the area of the big circle

If the radius of the small circle is 2cm long and the radius of the big circle is 5cm long, the perimeter of the small circle is 2 / 5 of the perimeter of the big circle, and the area of the small circle is 4 / 25 of the area of the big circle
The main reason is that the circumference is proportional to the radius
The area is proportional to the square of the radius