How long is the rattan?

I have seen this problem, too.

In fact, you spread out the whole rattan.

The rattan walked seven times along the circumference of 3*7=2 1 foot.

I walked 20 feet along the height again.

pythagorean theorem

Root number Root number (20*20+2 1*2 1)= root number 84 1 = about 45.5 feet.