Ab=45 mm,bc=10cm 4mm ,cd = 5 cm 6 mm ,de= 35 mm,ea=x cm, and the perimeter of irregular pentagon is 280 mm. find the length of the unknown side x in cm

The length of the unknown side x is 4 cm

Step-by-step explanation:

we know that

The perimeter of a polygon is equal to the sum of its length sides

Remember that

1 cm=10 mm

In this problem we have

AB=45 mm > convert to cm > AB=45/10=4.5 cm

BC=10 cm 4 mm > convert to cm > BC=10+4/10=10.4 cm

CD=5 cm 6 mm  > convert to cm > CD=5+6/10=5.6 cm

DE=35 mm > convert to cm > DE=35/10=3.5 cm

EA=x cm

P=280 mm > convert to cm > P=280/10=28 cm

The perimeter of the irregular polygon is equal to

P=AB+BC+CD+DE+EA

substitute the values

28=4.5+10.4+5.6+3.5+x

28=24+x

x=28-24

x=4 cm

Step-by-step explanation:

3y - 6 = 18

3y = 24

y = 8