Respuesta :

The third piece length is 0.81m

Step-by-step explanation:

Main length=5m

First length=2.34m

second length=1.85m

Third length=?

3rd length= main length-( 1st length + 2nd length)

=5m-(2.34m+1.85m)

=5m-4.19m

=0.81m