question 1 - You need to split the L shape into 2 shapes.
6mm x 2mm = 12mm
and
5mm x 2mm = 10mm
add 12mm and 10mm
the area is 22mm squared (a little 2 above the mm)
question 2 - you need to do the same
4mm x 2mm = 8mm squared
7mm x 2mm = 14mm squared
area - 22mm squared