a) 20 ft
b) 32 mm
Explanation:
a) The legs of the smaller triangle are 6-6-3. The larger triangle is 1/3 larger than the other triangle so the lengths of the legs are 8-8-4 so the perimeter is 20 ft.
b) Since one side of the larger square is 8 mm, this means that the perimeter is 4×8mm = 32 mm.