mathematical problem

1. The diameter of the small circle is 2cm, the radius of the big circle is 2cm, and the circumference of the small circle is the circumference of the big circle (1/2).

2. There are the following three punctuation marks on the school placard (the colored part in the picture). The radius of the great circle is r, the radius of the small circle is r, and R=2r. Now paint these punctuation marks separately. If the materials are uniform, which punctuation marks are painted the most? Which is the least? why

The first pi (r 2-r 2) = 3pi r 2.

The second pi (r 2/2 = 2pi r 2

The third PIR2-PI (R2-R2)/5 = 4pir2-3R2/5 =17R2/5 > 3pir 2 > 2pi r^2

The third has the most, the second the least, the third the largest and the second the smallest.