Calculate the length of the polyline MNKPEF if MN = 42mm, NK = 38mm, KP = 19mm, PE = 12mm, EF = 29mm.

In order to calculate the length of the polyline, you need to add all the segments.

So :

Add the segment MN and NK, that is, 42 mm + 38 mm = 80 (mm).

Add segment KP to PE, 19 mm + 12 mm = 31 (mm).

And the last action:

80 mm + 31 mm + 29 mm (segment EF) and we get the length of the broken line 140 (mm).

We can translate this into centimeters.

We know that 1 cm = 10 mm, hence it follows that 140 mm = 14 cm.