According to the conditions, the excircle is 10.8 mm, and the circumference of the excircle should be10.8 mm; The inner circle is 10.23 mm, that is, the circumference of the inner circle is10.23mm..

The pipe should be a cylinder, and the radius of the inner and outer circles can be calculated by the perimeter. When the length (that is, height) is known, the volume of the inner and outer cylinders (the volume formula of cylinders: bottom area × height) can be calculated, and then the volume of this pipe can be calculated. .

After the volume is calculated, the density can be calculated with the weight.