Calculate 3cm ,4cm, 10cm and 2cm

19cm

Step-by-step explanation:

(chose one way)

1. way using commutativity

(3cm+4cm)+(10cm+2cm)=7cm+12cm=19cm

2. way just writing

3cm+4cm+10cm+2cm=19cm

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.