we have a trapezoid and a triangle
area of trapezoid=(base1+base2) times 1/2height
area of traingle=1/2 base times height
triangle
base=18
height=12
area=1/2 times 12 times 18=108
trapezoid
to find height we do
17=12+height
subtrac 12
5=height
so
base1=14
base2=18
height=5
area=(14+18) times 1/2 times 5
area=32 times 1/2 times 5
area=80
total area=area of trapezoid+area of triangle
total area=80+108
total area=188 mm^2