Answer:20πmm
Step-by-step explanation:
each pencil diameter=10mm
each pencil diameter=radius Of The band
Radius of band=10mm
Circumference of band=2 x π x radius
Circumference of band=2xπx10
Circumference of band=20π
The length of band is the circumference Of The band
There length of band is 20πmm
Use Pythagorean thrm
17^2+10^2=21^2
289+100=441
389≠441
This is not a right triangle
For the first one it’s D.3
