5. (16m + 24) units
6. 380 small blocks
Explanations:
5.
Side in ABCD = 16m + 24
Side in EFGH = 3/4(Side in ABCD) = 3/4(16m + 24) = 12m + 18
Perimeter of ABCD = 4(16m + 24) = 64m + 96
Perimeter of EFGH = 4(12m + 18) = 48m + 72
Difference of perimeters = 64m + 96 - 48m - 72 = (16m + 24) units
6.
Large blocks : Small blocks = 3 : 20
57/Small blocks = 3/20
3 x Small blocks = 1140 (Cross multiplication)
Small blocks = 1140/3
Small blocks = 380